Design draft · Sources and assumptions identified · Deployment validation required
Contents
Edgecore deployment pattern · Customer version · 2026-11-03

Open Ethernet
Design Guide

Open Ethernet with Edgecore for HGX B300 and GB300 NVL72. Build an independent Ethernet fabric, or place Edgecore alongside the prescribed NVIDIA NCP design.

A proposed design with sources you can inspect. NVIDIA NVLink stays within the supported GPU domain. NCP compute fabrics retain the NVIDIA requirements; other Edgecore placements need deployment-specific acceptance. Read NVIDIA’s network requirements ↗

Performance is a validation target, not a promise of parity. Keep the evidence tags, test on the intended hardware and close the open items before deployment.

The document

Where this document is strong and where it is open

SectionVERIFIEDINFERREDUNKNOWN
OrientThe vocabulary, the two modes and the rules
1Speaking NVIDIA's language2022
2Two approaches, two platforms830
3HGX B300 and GB300 NVL72 compared951
4Design principles810
Open Ethernet with EdgecoreEdgecore replaces the east west fabric
5Open Ethernet with Edgecore on HGX B300: the rail block1672
6Open Ethernet with Edgecore on GB300 NVL72: an open scale out fabric7186
7Scaling past two tiers151
Fabric behaviourLossless and load balancing, measured honestly
8Congestion control and lossless configuration863
9Load balancing compared with Spectrum-X413
Alongside NVIDIA NCPEdgecore alongside NVIDIA NCP, plus the networks every build shares
10Edgecore alongside NVIDIA NCP20117
11Shared networks: frontend, storage and OOB1550
OperateNOS, telemetry and security
12SONiC software and NOS options720
13Operations and telemetry330
14Security and multitenancy302
Prove and buyThe test plan, the BOM and what is still open
15Validation plan300
16BOM structure (no prices)130
17Compliance matrix15912

Counts of the tags in each section, read from the document. Sections 18 and 19 are lists, so they carry no tags.

Orient

1The four networks and their roles

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NVIDIA describes an AI cluster in its own words, and it uses three sets of them. The NCP guides say TAN, CIN and SMN. The HGX Enterprise RA says converged, compute and out of band. The Inference RA says tenant access and cluster interconnect. They describe the same four networks. We use NVIDIA's names throughout this document so you can lay our design next to theirs and check every claim against the page we cite.

1.1 Four networks, three vocabularies

Network NCP guides [S1, S2] HGX Enterprise RA [S6] Inference RA [IRA] Mode A: open fabric Mode B: inside an NCP
NVLCINTANSMNScale up NVLink, "a proprietary NVIDIA standard" Not named on that page (NVLink inside the server [C1]) NVLink Domain NVIDIA NVIDIA
NVLCINTANSMNEast west CIN, Cluster Interconnect Network, "aka E/W", "Scale Out" GPU Compute (East/West) Network Cluster Interconnect Network Edgecore NVIDIA (Spectrum-X or Quantum)
NVLCINTANSMNNorth south TAN, Tenant Access Network, "aka N/S", "Front End" CPU Converged (North/South) Network Tenant Access Network Edgecore Edgecore underlay, BlueField-3 on the host
NVLCINTANSMNStorage The TAN's "primary consumer" Storage (North/South) connectivity Storage Domain Edgecore Edgecore
NVLCINTANSMNManagement SMN, Secure Management Network, "Ethernet (1GbE)" Out-of-band Management Networking Secure management traffic Edgecore Edgecore

Every NVIDIA term above is taken from the page in brackets, with NVIDIA's own spelling. VERIFIED [S1 "Networking"; S2 "Data Centre Networks"; S6 "Networking Logical Architecture"; IRA "Data Center Architecture" and "Networking"]. The inference provider requirements use a fourth pair of words for the same split: a "north-south plane on the BlueField-3 DPU" and an "east-west plane on the back-end RDMA fabric" VERIFIED [IPR "Networking and Multi-tenancy"]. The two ownership columns are this document's design, explained in section 2.

S1 adds one rule that holds in every NCP build: "The TAN and SMN are always Ethernet; the CIN can be configured as either Ethernet or InfiniBand, and NVLink is a proprietary NVIDIA standard." VERIFIED [S1 "Networking"].

1.2 Building block terms that collide

Term What NVIDIA means Source What this document does
Scalable unit (SU) 4 compute nodes in the HGX Enterprise RA: "scalable units (SU) based on 4 compute nodes" VERIFIED [S6 "Enterprise RA Scalable Unit (SU)"] Never says SU for its own block
Scalable unit (SU) 64 DGX B300 systems in DGX SuperPOD B300 VERIFIED [N1 Chapter 1] Same
Scalable unit (SU) 32 HGX nodes in Cisco's NCP Cloud RA VERIFIED [C2 "Two-tier East-West compute network"] Same
Rail block Not an NVIDIA term This document Edgecore's 32 node, 8 rail leaf building block on HGX B300 (section 5)
GPU POD A physical building block "containing up to 1152 GPUs" VERIFIED [S1 "Data Center View"] Used as NVIDIA defines it
Core POD Control nodes, general purpose nodes, high speed storage, the utility cluster and the DC edge cluster VERIFIED [S1 "Key Data Center View Components"] Used as NVIDIA defines it
Topology Block "A group of compute, network, storage, or supporting resources reserved or allocated as one unit" VERIFIED [R24 "Definitions"] Used as NVIDIA defines it
Provider profile The hardware profile an inference build follows: RTX PRO, HGX, GB300 NVL72, cloud hosted or lab VERIFIED [IRA "Architecture Decision Guardrails"] Mode A is a build that follows no NVIDIA profile
NVLink Domain "A uniquely identified set of GPUs or systems participating in a common NVLink® or NVSwitch connectivity and management domain" VERIFIED [R24 "Definitions"] Untouched in both modes

NVIDIA's POD is also not a Kubernetes pod, as S1 itself notes. VERIFIED [S1 "Data Center View" note].

1.3 How to read NVIDIA's requirements

  • Levels. The inference provider requirements follow RFC 2119: MUST and MUST NOT are mandatory, SHOULD is a strong recommendation, MAY is optional, and INFO rows "place no obligation on the NCP". VERIFIED [IPR "Purpose" tip]. The AI Clouds requirements use shall and must for mandatory and should for recommended. VERIFIED [R24 "Normative Language"].
  • Tables bind, prose explains. In the inference provider requirements, "The tables are the normative part of this document. The prose explains why a requirement exists ... it does not itself impose requirements." VERIFIED [IPR "Purpose" tip]. This matters in section 10, where one prose sentence names Spectrum switches and no table row does.
  • IDs collide between documents. The inference provider requirements number their network rows NET-1 to NET-8. The AI Clouds requirements v2.4 number theirs NET01 to NET06, and they mean different things: IPR NET-2 is the east west fabric, R24 NET02 is the NVLink Domain API. VERIFIED [IPR; R24 "Network Transport and Fabric Visibility"]. This document always names the document with the ID.
  • Scope. R24 is the bar for "NVIDIA Cloud Partners (NCP) delivering GPU capacity to NVIDIA", covering what is "needed to run NVIDIA DGX Cloud, expanding on the NVIDIA hardware reference design". VERIFIED [R24 "Purpose and Intent"]. The inference provider requirements apply to "an NVIDIA Cloud Partner (NCP) building a GB300 NVL72 compute cluster" for inference service providers. VERIFIED [IPR title and "Purpose"].
  • Gated documents decide some questions. The GB300 NVL72 Reference Design (IPR RD-2), the NCP storage reference design (IPR RD-3, STO-1) and the hardware reference for each inference profile are on NVIDIA's partner portal. VERIFIED [IPR "Reference Designs"; IRA "Physical Architecture"]. We haven't read them, and this document marks every question they decide as UNKNOWN.

1.4 How to read the tags in this document

Every load bearing claim carries one tag and a source in brackets.

  • VERIFIED: a primary source in section 19 says it (document plus section, table or page).
  • INFERRED: it follows from verified facts, and the arithmetic or reasoning is shown so anyone can check it. INFERRED means the math is right. It doesn't mean anyone has built it or NVIDIA has approved it.
  • UNKNOWN: no source we hold settles it. Section 18 says what would.
The four networks and their roles (NIC vs DPU) · detailed planning notes

(Mirrors Cisco: "HGX B300 Rack Server", "Networking topologies > Overview" [C1]; NVIDIA: Chapter 4 "Network Fabrics" [N1].)

#4.1 Per node network interfaces

Interface Count per node Speed Network Role Tag and source
NVIDIA B300 GPU 8 NVLink Scale up Inside the node only; NVIDIA owned VERIFIED [C1 "HGX B300 Rack Server"]
ConnectX-8 SuperNIC 8 (one per GPU) 2 x 400GbE breakout (800G per GPU) Backend compute (east west) RDMA data mover, GPUDirect VERIFIED [S6 Table 5: "configured for 2x400Gb Ethernet breakout"; C1 "Compute (Node East-West) Network"]
BlueField-3 B3240 DPU (or a ConnectX NIC in Mode A) 1 (Cisco allows 1 or 2) 2 x 400G Frontend converged (north south) Tenant, storage access, in band management; DPU runs overlays and isolation VERIFIED [S6 Table 5: 1x BF3 B3240; C1 Appendix A: "1x or 2x ... BlueField-3 B3240"]
Server BMC 1 1G OOB Redfish over TLS; IPMI disabled for v2.4 CNP10 VERIFIED [C1 "OOB Management Network"]
DPU BMC 1 per DPU 1G OOB DPU out of band management VERIFIED [C1 "OOB"; C2 "NVIDIA Bluefield-3 management network"]
Host management (x86) 2 (Cisco design) 10G OOB or in band management OS provisioning VERIFIED for Cisco [C1 "Topology with 16 compute nodes"]; Edgecore generic design does not count these, see Gaps

NIC vs DPU rule. The model does not tell you the network, the role does. ConnectX-8 is the backend card on B300; BlueField-3 is the frontend card [L Q3, VERIFIED]. DPUs are not used for backend connectivity in current NVIDIA designs [L Q4, INFERRED]. In the GB300 NVL72 provider profile, the BlueField-3 DPU path for north south traffic is a MUST [S3 NET-1, VERIFIED]. In Mode A a ConnectX NIC is acceptable on the frontend; the generic Edgecore design draws "CX7/BF3" [E4 slide 4], and the Enterprise RA family allows a ConnectX frontend card [L Q18, INFERRED].

#4.2 The four networks

Network NVIDIA NCP name Edgecore role, Mode A Edgecore role, Mode B Switch
Backend compute (scale out, east west) CIN Yes No (Spectrum-X or InfiniBand) AIS800-64O leaf and spine
Frontend converged (north south) TAN Candidate Proposed; acceptance UNKNOWN AIS800-64O leaf and spine
Storage part of TAN or a dedicated fabric Candidate Proposed; acceptance UNKNOWN AIS800-64O storage leaf pair
OOB management SMN Candidate Proposed; acceptance UNKNOWN EPS201 (48 x 1G); see section 16 and Gaps G5
NVLink (scale up) NVLink NVIDIA NVIDIA Not Ethernet

NCP names and the "TAN and SMN are always Ethernet; the CIN can be configured as either Ethernet or InfiniBand" rule: [S1 "Networking", VERIFIED].

Independent open EthernetIndependent open EthernetLogical network roles. Exact physical attachment depends on the selected platform.HGX B300 serverNVLink scale-up remains inside the NVIDIA domainNIC, DPU and management interfaces connect externallyCIN / ComputeAIS800-64O rail leaf + spine2 × 400G interfaces per CX-8TAN / FrontendAIS800-64O proposed leaf + spineSelected NIC / DPU attachmentSMN / ManagementRestricted management networkEPS201 candidate; size actual interfacesStorageConverged at 32 HGX nodes; dedicated as sizedBorder / DCIOptional external handoff; qualification required1:1 compute link budget is a design assumption, not a workload-performance guarantee.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 1. Mode A, the Open Ethernet AI Factory: all four networks on Edgecore.

Proposed placements around the NCP compute fabricProposed placements around the NCP compute fabricLogical network roles. Exact physical attachment depends on the selected platform.NVIDIA compute platform / selected profileNVLink scale-up remains inside the NVIDIA domainNIC, DPU and management interfaces connect externallyCIN / ComputePrescribed Spectrum-X or QuantumGB300 provider requirement NET-2TAN / FrontendAIS800-64O proposed leaf + spineSelected NIC / DPU attachmentSMN / ManagementRestricted management networkEPS201 candidate; size actual interfacesStorageConverged at 32 HGX nodes; dedicated as sizedBorder / DCIOptional external handoff; qualification requiredNCP: surrounding Edgecore placements are proposed, not accepted substitutions.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 2. Proposed placements only; GB300 NET-1/2 are scoped requirements, not a universal HGX acceptance verdict. Mode B, the NCP companion: Edgecore never touches the CIN without a written NVIDIA exception.

2Two approaches, two platforms

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Mode
Platform
FIG 1 · OWNERSHIP · FOUR NETWORKS · Open Ethernet with Edgecore on HGX B300Open Ethernet with Edgecore on GB300 NVL72Edgecore alongside NCP on HGX B300Edgecore alongside NCP on GB300 NVL72NVLCINTANSMNNVLCINTANSMNNVLCINTANSMNNVLCINTANSMN
TANNORTH SOUTHCOMPUTEHOSTSCINEAST WESTSMNMANAGEMENTTAN leaf and spineBGP underlay · EVPN · 2 x 400G per HGX nodeBGP underlay · EVPN · 2 x 200G per NVL72 trayEDGECOREStorage leavesRoCE classEDGECORECore PODcontrol · utilityEDGECOREBorder / DCIedge · NVIDIA POPEDGECOREHOST 1HGX B300 · 8 GPUNVL72 tray · 4 GPUNVLink domain8 GPUs72 GPUs per rackConnectX-8 · 800G8 per server4 per trayBlueField-32 x 400G2 x 200GHOST 2HGX B300 · 8 GPUNVL72 tray · 4 GPUNVLink domain8 GPUs72 GPUs per rackConnectX-8 · 800G8 per server4 per trayBlueField-32 x 400G2 x 200GHOST NHGX B300 · 8 GPUNVL72 tray · 4 GPUNVLink domain8 GPUs72 GPUs per rackConnectX-8 · 800G8 per server4 per trayBlueField-32 x 400G2 x 200GCIN leaf and spine · AIS800-64OCIN · Spectrum-X or Quantum InfiniBandrail optimized · 1:1 · 800G per GPUNVIDIA owned · IPR NET-2 on NVL72 NCP builds · Spectrum-X in the HGX ERAEDGECORESMN · 1G OOBBMC · DPU and SuperNIC BMC · switch mgmt · Redfish over TLSEDGECORENIC n to leaf n, one hop on railfrontend, dual homed
Edgecore suppliesNVIDIA ownedGated: needs written approvalHostsBackendFrontendOOB
Proposed network roles, not a cabling plan. Select an approach and platform to compare placements. NCP substitutions require deployment acceptance; brass marks additional gated design decisions.
HGX B300 GB300 NVL72
Mode A: open Ethernet AI factory. Edgecore replaces the east west fabric Every network on Edgecore: CIN, TAN, storage, SMN and border. Worked numbers in section 5. The build can't claim adherence to the HGX Enterprise RA, which is built on Spectrum-X switches. VERIFIED [S6 "Spine-Leaf Networking"] Edgecore CIN for scale out over ConnectX-8, NVLink untouched. Only outside an NCP engagement. Inside an NCP inference build, IPR NET-2 makes the CIN InfiniBand or Spectrum-X, a MUST. VERIFIED [IPR NET-2]. Numbers INFERRED, section 6
Mode B: NCP companion. Edgecore alongside NVIDIA NCP Edgecore TAN, storage and OOB next to a Spectrum-X CIN, measured against the HGX Enterprise RA. Section 10.5 Edgecore TAN underlay, storage leaves, SMN and Core POD switching next to NVIDIA's CIN, NVLink and BlueField. The gated GB300 NVL72 Reference Design decides acceptance. Section 10

Why Mode A can exist at all. NVIDIA's Inference RA hands the fabric choice to the hardware profile: "Treat RDMA, GPUDirect RDMA, dual-plane networking, BlueField use, and separate compute fabric as profile decisions instead of universal dependencies." VERIFIED [IRA "Architecture Decision Guardrails"]. For every profile it then says to "Confirm implementation details with the NVIDIA-approved, access-controlled hardware reference for the selected profile." VERIFIED [IRA "Physical Architecture"]. So the Inference RA doesn't call the fabric open, it defers. The only public requirement that names InfiniBand or Spectrum-X is IPR NET-2, which belongs to the GB300 NVL72 NCP profile. INFERRED. Mode A is for clusters that aren't built to an NVIDIA profile at all. Those clusters can still run NVIDIA's inference software, which IRA lists with public GitHub sources (Dynamo, NIXL, ModelExpress, KAI Scheduler, Grove, AIPerf). VERIFIED [IRA "Reference Component Version And Source Snapshot"]. How that software performs on an Edgecore fabric is ours to prove, not NVIDIA's to vouch for (sections 8 and 15).

Where the lock actually lives, so nobody is misled:

  • R24 never names InfiniBand, Spectrum, Quantum, ConnectX or a switch vendor for any network. The two NVIDIA networking names it does use are BlueField, in STG06 for BlueField JBOF storage, and "UFM event logs" in its list of required logs, which presumes an InfiniBand fabric manager where one exists. VERIFIED [R24 STG06, "Logs"].
  • R24 says a deployment agreement "does not waive or weaken a baseline requirement in this guide unless it expressly identifies the affected requirement and the approved exception." VERIFIED [R24 "Relationship to Deployment-Specific Requirements"]. That clause governs R24's own baseline, and R24 has no fabric vendor baseline to waive. INFERRED. The v1 draft of this document cited it as the gate on the east west fabric; that was wrong.
  • The vendor names come from the S2 reference table (CIN "InfiniBand (Quantum) or Ethernet (SpectrumX)", TAN "Ethernet (Spectrum)"), from IPR NET-2, and from the gated GB300 NVL72 Reference Design that IPR RD-2 makes a MUST. VERIFIED [S2 "Data Centre Networks"; IPR NET-2, RD-2].

3HGX B300 and GB300 NVL72 compared

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The networks are similar but not the same. Edgecore plays the same role on both and uses the same switch. What changes is the size of the NVLink domain, what a rack holds, and which NVIDIA document governs the build.

HGX B300 GB300 NVL72 Tag and source
Unit A server with 8 B300 SXM GPUs A rack of 18 compute trays and 9 NVLink switch trays; each tray has 4 B300 GPUs and 2 Grace CPUs VERIFIED [S6 Table 5; S1 "GPU Compute Node", "GPU Compute Rack"]
NVLink domain 8 GPUs, inside the server One domain per rack, so 72 GPUs (18 x 4) VERIFIED [C1 "HGX B300 Rack Server"; S1 "Networking"]; 72 INFERRED
East west NICs 8 ConnectX-8 SuperNICs at 800 GbE, "configured for 2x400Gb Ethernet breakout" 4 x 800Gb ConnectX-8 per tray, "Configurable to IB or Ethernet", so 72 per rack VERIFIED [S6 Table 5; S1]; 72 INFERRED
NVIDIA's own east west design Dual plane at 32, 64 and 128 nodes: "Each GPU has individual 400Gb connection to each plane" Dual plane networking is part of the GB300 NVL72 profile VERIFIED [S6 "32 Nodes", "64 Nodes", "128 Nodes"; IRA "Sizing Guidance"]
Frontend 1 BlueField-3 B3240 dual port 400 GbE, two ports "to two separate switches" "1 x 400GbE BF3 configured as 2x200GbE" per tray VERIFIED [S6 Table 5, "CPU Converged"; S1]
Frontend per GPU 800G / 8 GPUs = 100G 400G / 4 GPUs = 100G INFERRED arithmetic
OOB per unit "6x 1Gb/s connections" per server "1 x 1GbE" SMN per compute tray, plus NVLink switch trays, power shelves and cooling gear VERIFIED [S6 "Enterprise RA Scalable Unit"; S1]; rack total UNKNOWN
Cooling Servers per rack "depends on available rack power" The profile needs "liquid cooling" VERIFIED [S6 "32 Nodes"; IRA "Sizing Guidance"]
NVIDIA document that governs it HGX AI Factory Enterprise RA, built on Spectrum-X switches; the HGX inference profile defers to a gated hardware reference NCP software reference guides and the inference provider requirements, written for GB200 and GB300 NVL72 VERIFIED [S6; IRA "Physical Architecture"; S1; IPR]
Where the hardest traffic sits Tensor parallel stays inside 8 GPUs, so pipeline and expert parallel traffic cross the fabric more often Tensor parallel and large MoE models fit inside one 72 GPU rack; the fabric carries pipeline, expert, KV cache and weight traffic INFERRED from IPR AS-5: "TP within NVLink Domain, PP/EP within rack/IB partition" (an INFO row)

The practical difference: NVL72 moves the hardest GPU traffic onto NVLink inside the rack, so its east west fabric works more like an inference interconnect for KV cache and model movement. IRA describes the CIN as carrying "east-west model serving traffic, distributed inference coordination, model data movement, and high-volume cache or tensor movement". VERIFIED [IRA "Networking"]. HGX leans on the fabric harder, which is where Edgecore's 32, 64 and 256 node design lives. INFERRED.

4Design principles

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  1. One switch model for every 800G role. AIS800-64O for backend leaf and spine, frontend leaf and spine, and storage leaf. Fewer spares, one NOS image, one optic family. VERIFIED as design [E4 slide 3]. Cisco does the same with the N9364E-SG2-O. VERIFIED [C1 "Cisco N9364E-SG2-O"].
  2. Rail optimized backend. NIC n of every node lands on leaf n of its rail block, so same rail traffic is one hop. VERIFIED as design [E4 slide 4; N1 section 4.1].
  3. Nonblocking 1:1 backend. Leaf uplink bandwidth equals downlink bandwidth. VERIFIED as design [E4 slide 3].
  4. Separate networks for separate jobs. Backend, frontend, storage and OOB are separate fabrics, matching NVIDIA's four networks [S1] and Cisco's three fabric split plus storage leaves [C1 "Overview"].
  5. Cable the full block. If fewer nodes are bought, cable the full block's leaves and leaf to spine links, as NVIDIA advises: "the fabric should be designed to support the full SU, including leaf switches and leaf-spine cables". VERIFIED [N1 Chapter 4 intro, p.14].
  6. Plan the top tier on day one. If the cluster may pass the two tier ceiling, choose dual plane or three tier at the start. Cisco gives the same rule: customers who will scale beyond 8K GPUs "should deploy the compute network with a three-tier topology from the beginning". VERIFIED [C2 "East-West compute network"].
  7. 800G fabric links where possible. Prefer 1 x 800G ECMP links over 2 x 400G breakouts: more bandwidth per link tolerates hash collisions better. INFERRED; confirm on the customer's traffic in section 15 test 6.
  8. Optical in the 800G fabrics. No copper, for link integrity. VERIFIED as design assumption [E4 slide 2].
  9. Open and swappable software. ONIE on every switch, a SONiC based NOS, standard BGP and EVPN, no proprietary controller. VERIFIED [E1 "Software"].
  10. Don't touch NVLink. Scale up stays exactly as NVIDIA builds it, in both modes and on both platforms.
Open Ethernet with Edgecore

5HGX B300: rail topology, scalable units and sizing

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5.1 Per node network interfaces

Interface Count per node Speed Network Tag and source
NVIDIA B300 GPU 8 NVLink Scale up, NVIDIA owned VERIFIED [S6 Table 5; C1]
ConnectX-8 SuperNIC 8, one per GPU 800 GbE as 2 x 400G CIN, east west VERIFIED [S6 Table 5]
BlueField-3 B3240 DPU (or a ConnectX NIC in Mode A) 1 2 x 400 GbE, to two separate switches TAN, north south VERIFIED [S6 Table 5, "CPU Converged"]
1G management connections 6 per server: server BMC plus the BMCs of the BlueField-3 DPU and SuperNICs, and host management 1G OOB VERIFIED [S6 "Enterprise RA Scalable Unit", "Out-of-Band (OOB) Management Network"]; the per port split is INFERRED

The model doesn't tell you the network, the role does. ConnectX-8 is the backend card on B300 and BlueField-3 is the frontend card. VERIFIED [S6 Table 5]. In Mode A a ConnectX NIC is acceptable on the frontend; the generic Edgecore design draws "CX7/BF3". VERIFIED as design [E4 slide 4].

5.2 The rail block

One rail block is 32 HGX B300 nodes and the 8 AIS800-64O backend leaves that serve them, leaf n carrying GPU rail n of all 32 nodes. Each leaf uses 32 ports down (one 800G port per node) and 32 ports up. The rail block is the unit of growth, of tenant allocation and of failure isolation for same rail traffic. Spines are shared across rail blocks. VERIFIED as design [E4 slides 3 to 6, which call it "Scalable Units of 32 servers"].

Why 32: a 64 port 800G leaf split 1:1 gives exactly 32 node ports, so one leaf per rail fills to 100 percent at 32 nodes. INFERRED [E1 port count; E4 slide 3].

Why a new name: NVIDIA's HGX Enterprise RA uses SU for 4 nodes [S6], DGX SuperPOD for 64 systems [N1], and Cisco for 32 nodes [C2]. "POD" is NVIDIA's 1,152 GPU building block [S1]. Rail block collides with none of them. The Edgecore design deck still says "Scalable Units"; read that as rail blocks.

FIG 2 · MODE A · HGX B300 · 32 NODESNVLCINTANSMN
SPINE8x AIS800-64OLEAF8x AIS800-64OCOMPUTE32x HGX B300Spine 132/64 ports usedSpine 232/64 ports usedSpine 332/64 ports usedSpine 432/64 ports usedSpine 532/64 ports usedSpine 632/64 ports usedSpine 732/64 ports usedSpine 832/64 ports usedLeaf 1 · GPU032 down / 32 upLeaf 2 · GPU132 down / 32 upLeaf 3 · GPU232 down / 32 upLeaf 4 · GPU332 down / 32 upLeaf 5 · GPU432 down / 32 upLeaf 6 · GPU532 down / 32 upLeaf 7 · GPU632 down / 32 upLeaf 8 · GPU732 down / 32 upServer 18x CX-8 · 1x BF3Server 28x CX-8 · 1x BF3Server 38x CX-8 · 1x BF3Server 308x CX-8 · 1x BF3Server 318x CX-8 · 1x BF3Server 328x CX-8 · 1x BF3• • •32 serversRail optimized: NIC n of every server to leaf nFull mesh: 4 x 800G per leaf and spine pair
Edgecore suppliesNVIDIA ownedServers and partner systemsBackend 800G, shaded by railFrontendOOB 1G
Mode A rail block on HGX B300: ConnectX-8 n of every server lands on leaf n, and every leaf meets every spine with 4 x 800G. 16 switches, 1:1. VERIFIED as design [E4 slide 4].

5.3 Rail block math for 32, 64 and 256 nodes

Assumptions: 8 GPUs and 8 ConnectX-8 per node at 800G per GPU; 1 frontend card per node at 2 x 400G, dual homed; single plane backend; every 800G switch an AIS800-64O. VERIFIED as design [E4 slides 2, 3; S6 Table 5]. Counts are from the Edgecore design deck and the arithmetic is shown. VERIFIED [E4 slides 3 to 9].

18
AIS800-64O
32 HGX nodes, 256 GPUs
VERIFIED
30
AIS800-64O
64 HGX nodes, 512 GPUs
VERIFIED
110
AIS800-64O
256 HGX nodes, 2,048 GPUs
VERIFIED
1:1
BACKEND
800G per GPU, rail optimized
VERIFIED
32 nodes (1 rail block) 64 nodes (2) 256 nodes (8) Formula
GPUs 256 512 2,048 nodes x 8
ConnectX-8 backend NICs 256 512 2,048 nodes x 8
Frontend 400G links 64 128 512 nodes x 2
Backend leaves 8 16 64 nodes x 8 / 32
Leaf ports down / up 32 / 32 32 / 32 32 / 32 1:1
Backend spines 8 8 32 leaf uplinks / 64, headroom at 32 nodes
Spine ports used 256 of 512 512 of 512 2,048 of 2,048 leaves x 32
Backend switches 16 24 96 leaves + spines
Frontend and storage switches 2 6 14 see section 11.1
Total AIS800-64O 18 30 110 backend + frontend
Aggregate GPU injection bandwidth 204.8 Tbps 409.6 Tbps 1,638.4 Tbps GPUs x 800G, INFERRED

At 32 nodes the minimum is 4 spines (256 uplinks / 64 ports). The design keeps 8 spines half populated so a second rail block adds leaves only, and because "an underutilized fabric will help reduce congestion risks". VERIFIED as design choice [E4 slide 3, companion proposal deck notes].

5.4 Side by side with Cisco and NVIDIA (backend only)

Nodes Cisco single plane, 1 x 400G per GPU [C1 Table 2] Cisco dual plane, 2 x 400G per GPU [C1 Table 3] Edgecore single plane, 800G per GPU [E4]
16 2 + 0 4 + 0 4 + 0 minimum with two rails per leaf; 8 leaves if the full block is cabled (INFERRED)
32 4 + 2 8 + 4 8 + 8 (4 spines minimum)
64 8 + 4 16 + 8 16 + 8
128 16 + 8 32 + 16 32 + 16 (INFERRED: 4 rail blocks, 1,024 uplinks / 64)
256 not covered not covered 64 + 32

Per GPU backend bandwidth is the same 800G in Cisco's dual plane design, NVIDIA's dual plane HGX design and Edgecore's single plane design. INFERRED from the cited tables and [S6].

5.5 Dual plane variant

NVIDIA's own HGX B300 design is dual plane at every size it documents: "Each GPU has individual 400Gb connection to each plane via 800Gb port broken out to 2x400Gb". VERIFIED [S6 "32 Nodes", "64 Nodes", "128 Nodes"]. Cisco also recommends it "to avoid a single point of failure". VERIFIED [C1 "Compute (Node East-West) Network"]. On AIS800-64O the switch counts at 64 and 256 nodes are unchanged (each plane has half the leaves and half the spines, and leaf ports run 2 x 400G toward nodes); at 32 nodes the minimum becomes 8 leaves and 4 spines. INFERRED arithmetic. NVIDIA's dual plane failover relies on the ConnectX-8 "onboard plane load balancer unit" and "NVIDIA Route software". VERIFIED [N1 section 4.1]. Whether that works behind a non NVIDIA switch is UNKNOWN (gap G3).

5.6 Optics count

Optic (part number per E4) Use 32 nodes 64 nodes 256 nodes
ET8001-2DR4, OSFP 800G 2xDR4 Backend leaf ports 512 1,024 4,096
ET8001-2DR4 Backend spine ports 256 512 2,048
ET8001-2DR4 ConnectX-8 NIC ports 256 512 2,048
ET8001-2DR4 Frontend and storage switch ports 64 192 576
ET8001-2DR4 total 1,088 2,240 8,768
ET7512-DR4, QSFP112 400G DR4 Frontend card ports, 2 per node 64 128 512

VERIFIED as design counts [E4 slides 7 to 9]. The optic specifications are UNKNOWN here because no Edgecore transceiver datasheet is in the library. Two specific unknowns: whether the NIC side optic has the riding heat sink form the ConnectX-8 cage needs (Cisco uses a distinct OSFPR part on ConnectX-8 [C1 Table 1, VERIFIED]), and ConnectX-8 interoperability of the Edgecore optic. NVIDIA recommends a "Dual-ported optic ... to simplify breakout at NVIDIA ConnectX-8 OSFP port". VERIFIED [S6 "64 Nodes"]. See gap G4.

The scalable unit (SU) · detailed planning notes

(Mirrors Cisco: "Two-tier East-West compute network" SU definition [C2]; NVIDIA: "scalable units (SU)" [N1 Chapter 1].)

"SU" is defined per design and the sizes differ. Say which SU you mean.

Design SU size Source
Edgecore (this document) 32 HGX B300 nodes, 256 GPUs, 8 rail leaves E4 slides 5, 6 ("Scalable Units of 32 servers"), VERIFIED as design
Cisco Cloud RA (NCP, HGX H200) 32 HGX nodes, 256 GPUs, leaves in rail groups 1+5, 2+6, 3+7, 4+8 C2 "Two-tier East-West compute network", VERIFIED
NVIDIA DGX SuperPOD B300, Spectrum-4 Ethernet 64 DGX B300 systems per SU N1 Chapter 1 p.2 and Table 3.1, VERIFIED
NVIDIA HGX B300 Enterprise RA Sized 4 to 128 compute nodes; exact SU wording not quoted L Q7, INFERRED

Edgecore SU definition (local 32-server rail group). One SU is 32 HGX B300 nodes and the 8 AIS800-64O backend leaves that serve them, leaf n carrying GPU rail n of all 32 nodes. Each leaf uses 32 ports down (one 800G port per node) and 32 ports up. The rail group is a growth unit. Tenant isolation and failure boundaries need an explicit implementation and are not guaranteed by this grouping. Spines are shared across SUs. [E4 slides 3 to 6]

Why 32: a 64 port 800G leaf split 1:1 gives exactly 32 node ports, so one leaf per rail fills to 100 percent at 32 nodes. INFERRED [E1 port count; E4 slide 3]. Glossary note: Edgecore SEs may also say "pod" or "rail group" for this block to avoid confusion with NVIDIA's SU [glossary "SU"].

SU math for 32, 64 and 256 nodes · detailed planning notes

(Mirrors Cisco: Tables 2, 3, 4 and "Topology with N compute nodes" [C1].)

Assumptions: 8 GPUs and 8 ConnectX-8 per node at 800G per GPU (2 x 400G); 1 frontend card per node at 2 x 400G, dual homed; single plane backend; all switches AIS800-64O except OOB [E4 slides 2, 3; S6 Table 5]. Counts below are VERIFIED against the generic Edgecore design deck [E4 slides 3 to 9] and the arithmetic is shown.

#6.1 Compute, NICs and backend switches

32 nodes (1 SU) 64 nodes (2 SU) 256 nodes (8 SU) Formula
GPUs 256 512 2,048 nodes x 8
ConnectX-8 backend NICs 256 512 2,048 nodes x 8
Backend links at 800G (each 2 x 400G) 256 512 2,048 one per NIC
Frontend cards (BF3 or ConnectX) 32 64 256 nodes x 1
Frontend 400G links 64 128 512 nodes x 2
Backend leaves 8 16 64 nodes x 8 / 32
Leaf ports down / up 32 / 32 32 / 32 32 / 32 1:1
Backend spines 8 8 32 leaf uplinks / 64, with headroom at 32 nodes
Spine ports used 256 of 512 512 of 512 2,048 of 2,048 leaves x 32
Links per individual leaf–spine pair 4 4 1 32 / spines
Backend switches 16 24 96 leaves + spines
Backend oversubscription 1:1 1:1 1:1 leaf up = leaf down
Aggregate GPU injection bandwidth 204.8 Tbps 409.6 Tbps 1,638.4 Tbps GPUs x 800G, INFERRED

At 32 nodes the minimum is 4 spines (256 uplinks / 64 ports). The generic design keeps 8 spines at half population so a second SU adds leaves only, and because "an underutilized fabric will help reduce congestion risks" [E4 slide 3; companion proposal deck notes, slide 7]. VERIFIED as design choice.

#6.2 Frontend, storage and total switches

Capacity boundary. Frontend figures below sum port line rates. Two 400G BlueField ports do not establish 800G usable card throughput. Confirm the exact card limit and profile. The 64/256-node frontend is 2:1, and storage uplink figures are upper bounds. [S6, S7; INFERRED sizing, UNKNOWN delivered performance]

32 nodes 64 nodes 256 nodes
Frontend design 2 frontend switches, storage attached to them 2 frontend spines + 2 compute frontend leaves + 2 storage leaves 4 frontend spines + 8 compute frontend leaves (1 pair per 64 nodes) + 2 storage leaves
Frontend and storage AIS800-64O 2 6 14
Compute frontend leaf oversubscription n/a (no spine tier) 2:1 (32 ports down as 64 x 400G, 16 x 800G up) 2:1 (32 down, 16 up)
Storage leaf uplinks n/a 2 x 16 x 800G = 25.6 Tbps 2 x 16 x 800G = 25.6 Tbps
Storage uplink per GPU sized by storage ports 50 Gbps 12.5 Gbps
Total AIS800-64O 18 30 110

Source: E4 slides 3, 5 to 9, VERIFIED as design; per GPU storage figures INFERRED (25.6 Tbps / GPUs). For comparison Cisco pre allocates storage facing ports for "12.5 gbps of network bandwidth per GPU" [C1 "Converged (Node North-South) Network", VERIFIED]; the 256 node Edgecore design lands on the same figure and the 64 node design exceeds it. The deck labels frontend and storage counts as "estimates, before final storage sizing" [E4 slide 3].

Why 256 nodes needs 8 frontend leaves and 4 spines: with 6 leaves each would need 43 ports down plus 22 up, which is 65 of 64 ports; with 2 spines each would need 80 ports [E4 slide 9, companion proposal deck notes, VERIFIED arithmetic].

#6.3 OOB management

The original deck's 2 / 3 / 8 switch estimate counts too few management interfaces for the six-port HGX assumption used here. The corrected comparison is:

32 nodes 64 nodes 256 nodes
Server management ports, 6 per server 192 384 1,536
Data-switch management ports 18 30 110
Storage management, illustrative 4 8 16
Total before additional infrastructure 214 422 1,662
Minimum 48-port switches 5 9 35

Generic rounding rule: ceil(management ports / 48) [E4 slide 3, VERIFIED]. Interface coverage is INFERRED from S6 and Cisco's port list [C1 "Topology with 16 compute nodes"]. These are planning minima, not a released BOM. Add actual OEM interfaces, control servers, PDUs, CDUs, console equipment, OOB-switch management, spare capacity and rack distribution. Cisco's 10G host management needs a separate port-speed decision. Mode B must rederive the retained NVIDIA backend management count. See Gaps G7.

#6.4 Optics count

Optics boundary. Counts from E4 are provisional. Reconcile physical cages, 2 x 400G logical interfaces, NIC form factors, storage downlinks and management uplinks before ordering. No optic interoperability is established. [E4; UNKNOWN final cable schedule]

Optic (part number per E4) Use 32 nodes 64 nodes 256 nodes
ET8001-2DR4, OSFP 800G 2xDR4 Backend leaf ports 512 1,024 4,096
ET8001-2DR4 Backend spine ports 256 512 2,048
ET8001-2DR4 ConnectX-8 NIC ports 256 512 2,048
ET8001-2DR4 Frontend and storage switch ports 64 192 576
ET8001-2DR4 total 1,088 2,240 8,768
ET7512-DR4, QSFP112 400G DR4 Frontend card ports (2 per node) 64 128 512
TBD Storage leaf downlinks in frontend count TBD TBD
none OOB: Cat6 copper n/a n/a n/a

Source: E4 slides 7 to 9, VERIFIED as design counts. Part numbers come from the Edgecore design deck; the optics specifications are UNKNOWN for this document because no transceiver datasheet sits in the datasheet library [rule: Edgecore specs only from datasheets]. Two specific unknowns: (a) whether the NIC side optic has the flat top, riding heat sink form the ConnectX-8 cage needs (Cisco uses a distinct OSFPR riding heat sink part on ConnectX-8 and an integrated heat sink part on switches [C1 Table 1, Table 5, VERIFIED]); (b) ConnectX-8 interoperability of the Edgecore optic. See Gaps G4.

#6.5 Side by side with Cisco (backend only)

Nodes Cisco single plane, 1 x 400G per GPU (leaf + spine) [C1 Table 2] Cisco dual plane, 2 x 400G per GPU [C1 Table 3] Edgecore single plane, 800G per GPU [E4]
16 2 + 0 4 + 0 4 + 0 minimum with two rails per leaf, as Cisco does; 8 leaves if the full SU is cabled per NVIDIA guidance (INFERRED)
32 4 + 2 8 + 4 8 + 8 (4 minimum)
64 8 + 4 16 + 8 16 + 8
128 16 + 8 32 + 16 32 + 16 (INFERRED: 4 SU, 1,024 uplinks / 64)
256 not covered not covered 64 + 32

Per GPU backend bandwidth is the same (800G) in Cisco's dual plane design and Edgecore's single plane design; switch counts match at 64 and 128 nodes. INFERRED from the cited tables.

#6.6 Dual plane variant (optional)

Rail mapping condition. The equal-count dual-plane proposal below requires pairing two 400G rails on each leaf. Keeping one rail per leaf changes the count. A complete endpoint map and failure test are required. [C1; INFERRED topology, UNKNOWN validation]

NVIDIA and Cisco both recommend dual plane: each ConnectX-8 sends one 400G port to each of two independent planes [C1 "Compute (Node East-West) Network": "dual plane fabric is recommended to avoid a single point of failure"; N1 section 4.1, VERIFIED]. With the rail-pair packing condition above, on AIS800-64O the switch counts at 64 and 256 nodes are unchanged (each plane has half the leaves and half the spines, leaf ports run 2 x 400G toward nodes). At 32 nodes the minimum becomes 8 leaves + 4 spines. INFERRED arithmetic. NVIDIA's dual plane failover relies on the ConnectX-8 "onboard plane load balancer unit" and "NVIDIA Route software" [N1 section 4.1, VERIFIED]; whether that behavior works with a non NVIDIA switch is UNKNOWN (Gaps G3).

Rail optimized topology per network · detailed planning notes

(Mirrors Cisco: "Topology with 32 / 64 / 128 compute nodes" and Figures 8 to 10 [C1].)

#7.1 Backend, one SU (32 nodes)

Each node's ConnectX-8 n connects to leaf n. Each leaf has 32 node ports and 32 spine ports; every leaf connects to every spine with 4 x 800G. [E4 slide 4, VERIFIED]

32-server rail group32-server rail group256 GPUs · single-plane sizing baseline · one 800G cage budget per GPU (2 × 400G interfaces)8 × AIS800-64O spines32 of 64 ports used per spine; headroom reserved for expansion4 × 800G per individual leaf–spine relationshipLeaf 1GPU rail 032 ports down / 32 ports upLeaves 2–7GPU rails 1–632 ports down / 32 ports upLeaf 8GPU rail 732 ports down / 32 ports up32 × HGX B300 serversEach NIC connects to its assigned rail leaf. See the endpoint schedule before cabling.Grouped links show relationships, not individual fiber assemblies. Inter-leaf mesh is represented as a tier.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 3. Backend, 32 nodes: 8 rail leaves, 8 spines, 1:1.

#7.2 Backend, 256 nodes (8 SUs)

Eight rail groups, one compute fabricEight rail groups, one compute fabric256 HGX servers · 2,048 GPUs · 64 leaves + 32 spines32 × AIS800-64O spines64 of 64 ports used per spineEach leaf: 1 × 800G to every spineRail group 1Servers 1–32Leaves 1–8Rail groups 2–7Six further 32-server groupsEight rail leaves per groupRail group 8Servers 225–256Leaves 57–64One-hop same-rail traffic is local to a shared leaf group. Inter-group traffic traverses the spine tier.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 4. Backend, 256 nodes: 64 leaves, 32 spines, 2,048 leaf uplinks = 32 x 64 spine ports, 1:1 [E4 slide 6].

Same rail traffic stays inside the SU leaf (one hop). Cross rail and cross SU traffic crosses the spine. These are topology observations, not collective-performance results. [section 7 diagram, INFERRED]

#7.3 Frontend and storage (64 and 256 nodes)

Frontend and storage at 64 / 256 HGX serversFrontend and storage at 64 / 256 HGX serversProposed Ethernet design. Host attachment and NCP acceptance are profile-specific.Border / DCIExternal routing and handoffFrontend spines2 spines at 64 servers / 4 spines at 256 servers · AIS800-64OCompute frontend leaf pairOne pair per 64 servers16 × 800G uplinks per leaf · 2:1Storage leaf pairPartner-specific downlinks16 × 800G uplinks per leafHGX servers2 × 400G nominal links; confirm card aggregate limitPartner storage serversMeasure delivered throughput and failure behaviorAt 32 servers, storage attaches to the frontend pair. Link rates do not establish application throughput.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 5. Frontend converged fabric with dedicated storage leaves [E4 slides 5, 6]. At 32 nodes, the two frontend switches carry nodes and storage directly.

#7.4 OOB management

Secure infrastructure managementSecure infrastructure managementIllustrative aggregation. Switch quantity must come from the complete port schedule.Server & DPU managementActual OEM management interfacesNetwork & facility devicesSwitches, PDUs, CDUs, consolesAdditional control servicesControl hosts and storage managementEPS201 access tier48 × 1G access ports5 / 9 / 35 planning minima*Restricted aggregation25G / 100G uplink optionsSeparate management VRF*32 / 64 / 256 HGX servers at six ports each, plus listed data-switch and storage management.Add other devices and reserve. 10GBASE-T and secure-boot requirements need separate resolution.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 6. Illustrative management tiers, not a two-switch BOM. OOB management. EPS201 ports from [E3]. Cisco uplinks OOB leaves to the converged spines [C1 "OOB"]; NVIDIA rolls OOB into the spine layer "as a dedicated VXLAN" [N1 section 4.4.2]. The OOB VRF is never exposed to tenants [C2 "Multitenancy"].

6Open Ethernet with Edgecore on GB300 NVL72: an open scale out fabric

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This section applies only to GB300 NVL72 bought outside an NCP engagement. Inside an NCP inference build, the CIN is InfiniBand or Spectrum-X, a MUST. VERIFIED [IPR NET-2]. No public NVIDIA document forbids an Ethernet CIN on a non NCP NVL72 build, and none blesses it either. INFERRED.

6.1 What one rack brings

Per rack Count Arithmetic Tag and source
GPUs 72 18 trays x 4 VERIFIED per tray [S1]; INFERRED total
ConnectX-8 at 800G on the CIN 72 18 trays x 4 VERIFIED per tray [S1]; INFERRED total
CIN bandwidth 57.6 Tbps 72 x 800G INFERRED
BlueField-3 at 400 GbE as 2 x 200 GbE on the TAN 18 cards, 36 x 200G ports 18 trays x 1 VERIFIED per tray [S1]; INFERRED total
TAN bandwidth 7.2 Tbps 18 x 400G INFERRED
SMN 1G from compute trays 18 18 trays x 1 VERIFIED per tray [S1]; NVLink switch trays, power shelves and cooling ports UNKNOWN
72
800G PORTS
CIN per NVL72 rack, 18 trays x 4
INFERRED
57.6
TBPS
CIN per rack, 72 x 800G
INFERRED
54
AIS800-64O
backend for one 16 rack POD
INFERRED
28
RACKS
two tier ceiling, 2,016 GPUs
INFERRED

6.2 Scale out math on AIS800-64O

Assumptions: every ConnectX-8 port runs 1 x 800G; single plane; each leaf runs 1:1 with 32 ports down and 32 up; a 64 port spine. All of it INFERRED arithmetic from [S1] and [E1].

1 rack 4 racks 16 racks, one full GPU POD 28 racks, two tier ceiling Formula Tag
GPUs 72 288 1,152 2,016 racks x 72 INFERRED
800G CIN endpoints 72 288 1,152 2,016 racks x 72 INFERRED
Leaves 3 (2.25 rounded up) 9 36 63 endpoints / 32 INFERRED
Spines 2 5 18 32 leaves x 32 / 64, rounded up INFERRED
Backend switches 5 14 54 95 leaves + spines INFERRED
800G optic ports in use 288 1,152 4,608 8,064 NIC + leaf down + leaf up + spine, 4 per endpoint INFERRED

Why 16 racks is one POD: S1 sizes a GPU POD at "up to 1152 GPUs", and 1,152 / 72 = 16. VERIFIED [S1]; INFERRED arithmetic. Why 28 racks is the ceiling: a 64 port switch in two tiers serves 64 x 64 / 2 = 2,048 endpoints, and 28 racks (2,016) is the most whole racks under that. INFERRED. Beyond that, the options are the same as on HGX (section 7). A dual plane build with each ConnectX-8 at 2 x 400G halves the per plane radix use and doubles the ceiling in endpoints. INFERRED, and the ConnectX-8 plane failover behind a non NVIDIA switch is UNKNOWN (gap G3).

FIG 3 · MODE A · GB300 NVL72 · 16 RACKSNVLCINTANSMN
SPINE18x AIS800-64OLEAF36x AIS800-64ONVL72 RACKS16 per GPU PODSpine 11:1Spine 21:1Spine 31:1Spine 41:1Spine 51:1Spine 61:1… Spine 18INFERREDLeaf 132 / 32Leaf 232 / 32Leaf 332 / 32Leaf 432 / 32Leaf 532 / 32Leaf 632 / 32Leaf 732 / 32Leaf 832 / 32… Leaf 36INFERREDRack 1NVLINK72 x 800GRack 2NVLINK72 x 800GRack 3NVLINK72 x 800GRack 14NVLINK72 x 800GRack 15NVLINK72 x 800GRack 16NVLINK72 x 800G• • •16 racks · 1,152 GPUsRail mapping UNKNOWN (gated) · 1,152 endpoints / 32 = 36 leaves36 leaves x 32 uplinks / 64 = 18 spines
Edgecore suppliesNVIDIA ownedServers and partner systemsBackend 800G, shaded by railFrontendOOB 1G
Open Ethernet with Edgecore on one GB300 NVL72 GPU POD of 16 racks: 1,152 endpoints on 36 leaves and 18 spines. Every count is INFERRED arithmetic (section 6.2). NVLink switch trays stay NVIDIA's. Rail mapping UNKNOWN.

6.3 What stays UNKNOWN on NVL72

  • Rail mapping. How NVIDIA maps the 72 ConnectX-8 ports per rack to rails is in the gated GB300 NVL72 Reference Design. UNKNOWN (gap G16). The leaf and spine counts above hold for any mapping that keeps 32 ports down per leaf. INFERRED.
  • NVL72 traffic mix on Tomahawk 5. NIXL KV transfer and Dynamo disaggregated serving on a RoCEv2 fabric with Tomahawk 5 and ConnectX-8: no published result. UNKNOWN (gap G1, G2).
  • Management port count per rack. Beyond the 18 compute tray ports, UNKNOWN (gap G19).

6.4 A sizing target that doesn't name a vendor

For inference, IPR gives one east west number any fabric can be held to: pull weights "fast enough to hydrate a cold node (~400 GB 405B FP8) in under 60 s". VERIFIED [IPR KUB-38, a SHOULD]. That's about 6.7 GB/s, or about 53 Gbps per node, against 800G per GPU on this fabric. INFERRED arithmetic. The hard part is the transfer software and the lossless profile, not the bandwidth.

7Superspine scaling beyond two tiers

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256 HGX nodes is the largest two tier, single plane, 800G fabric with AIS800-64O: 64 leaves x 32 uplinks = 2,048 = 32 spines x 64 ports, every spine port used. INFERRED arithmetic [E1; E4 slide 6]. The same ceiling is 28 NVL72 racks (section 6.2). Three ways to grow:

Option How Max GPUs Switches at 1,024 HGX nodes (8,192 GPUs) Trade off Tag
A. Dual plane, 400G radix, two tier Each ConnectX-8 400G port to a different plane; leaf 64 x 400G down, 64 x 400G up; spine 128 x 400G 8,192 (k = 128 logical ports) 256 leaves + 128 spines = 384 Fabric links at 400G; plane failover behind a non NVIDIA switch UNKNOWN INFERRED
B. Three tier super spine, 800G Pod = 4 rail blocks (128 nodes) = 32 leaves + 32 pod spines (32 down, 32 up); 32 super spine planes 65,536 (k cubed / 4, k = 64) 256 leaves + 256 spines + 128 super spines = 640 More switches and optics, one more hop INFERRED
C. Higher radix silicon Edgecore has announced 102.4T Tomahawk 6 switches, the AIS1600-64O and AIS800-128O [E8] n/a n/a No datasheet in our library yet; specs not used here announced only

Worked example for option B at 512 HGX nodes (4,096 GPUs): 4 pods, 128 leaves, 128 pod spines, 64 super spines (4 pods x 32 spines x 32 uplinks = 4,096 / 64), 320 switches. INFERRED arithmetic. Cisco builds the same shape: "an SU-group of four Scalable Units" with super spine groups. VERIFIED [C2].

FIG 4 · SCALE · THREE TIER OPTIONNVLCINTANSMN
SUPER SPINE32 planesPOD SPINE32 per podRAIL LEAF32 per podPlane 1super spinesPlane 2super spinesPlane 3super spines… Plane 32super spinesPod 1 · 4 rail blocks · 128 nodesS132 / 32L1rail leafS232 / 32L2rail leafS3232 / 32L32rail leafPod 2 · 4 rail blocks · 128 nodesS132 / 32L1rail leafS232 / 32L2rail leafS3232 / 32L32rail leaf… Pod N · 4 rail blocks · 128 nodesS132 / 32L1rail leafS232 / 32L2rail leafS3232 / 32L32rail leafpod spine j connects to plane j
Edgecore suppliesNVIDIA ownedServers and partner systemsBackend 800G, shaded by railFrontendOOB 1G
Option B: pods of four rail blocks under 32 super spine planes, up to 65,536 GPUs with 64 port switches. INFERRED arithmetic (section 7).

In Mode B, the super spine is part of the CIN and stays NVIDIA's. A Tomahawk super spine over NVIDIA leaves forfeits Spectrum-X features on paths that cross it and isn't addressed by any NCP page we read. INFERRED [L Q13].

Super spine scaling · detailed planning notes

(Mirrors Cisco: "Three-tier East-West compute network" [C2].)

256 nodes is the largest two tier, single plane, 800G fabric with AIS800-64O: 64 leaves x 32 uplinks = 2,048 = 32 spines x 64 ports, every spine port used. For a 64 port switch, two tier capacity is k squared over 2 = 2,048 endpoints. INFERRED arithmetic from [E1] port count and [E4] slide 6. Three ways to grow:

Option How Max GPUs Switches at 1,024 nodes (8,192 GPUs) Trade off Tag
A. Dual plane, 400G radix, two tier Each CX-8 port (400G) to a different plane; leaf runs 64 x 400G down, 64 x 400G up; spine 128 x 400G 8,192 (k = 128 logical ports) 256 leaves + 128 spines = 384 Fabric links at 400G; plane failover behavior with non NVIDIA switches and comparative performance UNKNOWN INFERRED
B. Three tier super spine, 800G Pod = 4 SUs (128 nodes) = 32 leaves + 32 pod spines (32 down, 32 up); 32 super spine planes 65,536 (k cubed over 4, k = 64) 256 leaves + 256 spines + 128 super spines = 640 More switches and optics, one more hop; 800G everywhere INFERRED
C. Next generation switch Higher radix silicon n/a n/a Roadmap is out of scope not covered

Worked example for option B at 512 nodes (4,096 GPUs): 4 pods, 128 leaves, 128 pod spines, 64 super spines (4 pods x 32 spines x 32 uplinks = 4,096 / 64), 320 switches; optics ports in use 4,096 NIC + 8,192 leaf + 8,192 pod spine + 4,096 super spine = 24,576. INFERRED arithmetic.

Three-tier expansion conceptThree-tier expansion conceptTheoretical capacity model. No validated deployment at this scale is claimed.Super-spine tier / 32 planesSpine j in each pod connects to plane jPod 1 · 32 pod spines32 ports down / 32 ports upPod N · 32 pod spinesUp to 64 pods in the mathematical model32 rail leaves128 servers per pod · four local rail groups32 rail leavesRequires routing, cable and failure-domain designFull-radix arithmetic is not evidence of supported routing scale, operational feasibility or workload performance.
Legend:EdgecoreNVIDIA or partner hardwareNVIDIA owned fabric

Figure 7. Theoretical scaling concept; no deployment validation at this scale is claimed. Three tier option. Cisco builds the same shape: "an SU-group of four Scalable Units" with "four groups" of super spine [C2, VERIFIED]; the Edgecore pod is the same 4 SU grouping.

Mode B note. Inside an NCP or Spectrum-X RA, the super spine is part of the CIN and stays Spectrum-X or InfiniBand. A Tomahawk super spine over NVIDIA leaves forfeits Spectrum-X features on paths that cross it and is not addressed by any NCP page we read [L Q13, INFERRED].

Fabric behaviour

8Congestion control and lossless configuration

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8.1 Starting profile

Parameter Starting value Source and tag
Transport RoCEv2 VERIFIED [E1 "AI/ML Clusters"]
RDMA traffic class DSCP 26 VERIFIED [C4 p.5]
CNP class DSCP 48, queue 6 VERIFIED [C4 p.5]
PFC Enabled on priority queue 3 only VERIFIED [C4 p.5]
Global link level flow control Disabled: "must not be enabled" VERIFIED [C4 p.5]
ECN marking Enabled, WRED style thresholds, start at 1 percent mark probability and tune on real traffic INFERRED (a starting point, not a measured profile)
Host reaction point DCQCN on ConnectX-8 INFERRED (standard RoCEv2 practice); ConnectX-8 settings with AIS800 UNKNOWN
PFC watchdog Enabled INFERRED (the standard guard against PFC deadlock)
MTU Jumbo, up to 9,416 bytes VERIFIED [E1 "Performance"]
Buffer Tomahawk 5 "Advanced shared buffering" VERIFIED [E1]; buffer profile values UNKNOWN

8.2 What Edgecore has published

The public result is Edgecore's AIS800-64O and Enterprise SONiC test on AMD MI300X with Broadcom Thor 2 NICs: "Nonblocking (1:1): Up to 35.6% improvement" in collective performance with congestion aware packet spraying, with up to 26.7% at 2:1. VERIFIED [E9]. It's AMD GPUs and Broadcom NICs, not ConnectX-8, so it shows what the switch and NOS can do and doesn't stand in for the B300 validation in section 15.

  • Tuning method: run PFC only for a baseline, enable ECN and watch queue depth, set thresholds from observed buffer use so the mark rate doesn't hit 100 percent too early, then adjust mark probability. INFERRED (standard RoCEv2 practice).
  • PFC alone reacts to congestion faster than ECN but can deadlock, which is why the watchdog stays on and ECN is added. INFERRED.
  • Thresholds must be tuned on the customer's real traffic. INFERRED.

8.3 The open item

A validated Tomahawk 5 plus ConnectX-8 RoCEv2 lossless profile (PFC, ECN thresholds, buffer profile, DCQCN parameters) is UNKNOWN [L Q24]. It's the deciding item for Open Ethernet with Edgecore on both platforms and the first step of the validation plan (section 15).

Congestion control and lossless configuration · detailed planning notes

(Cisco's Enterprise RA has no dedicated section; its storage RA specifies RoCEv2 QoS [C4]. NVIDIA: section 4.1 [N1].)

#9.1 Starting profile

Parameter Starting value Source and tag
Transport RoCEv2 E1 "AI/ML Clusters", VERIFIED
RDMA traffic class DSCP 26 C4 p.5 (storage), VERIFIED; application to this compute fabric INFERRED
CNP class DSCP 48, queue 6 C4 p.5, VERIFIED
PFC Enabled on priority queue 3 in the cited storage profile C4 p.5, VERIFIED for that profile; deployment configuration requires validation
Global link level flow control Disabled C4 p.5: "must not be enabled", VERIFIED
ECN marking Deployment-specific configuration; no numeric defaults established here UNKNOWN; section 15 validation plan
ECN thresholds To be set from workload and buffer validation UNKNOWN; section 15 validation plan
Host reaction point DCQCN on ConnectX-8 INFERRED (standard RoCEv2 practice); CX-8 settings with AIS800: UNKNOWN
PFC watchdog Confirm NOS support and validate recovery behavior UNKNOWN support and settings; section 15 validation plan
MTU Jumbo, up to 9,416 bytes supported E1 "Performance", VERIFIED
Buffer TH5 "advanced shared buffering" E1, VERIFIED; buffer profile values UNKNOWN

#9.2 Validation boundary

This public review edition does not include benchmark results from restricted test material. No job-time, latency or comparative link-performance result is established by this document. Test the selected switches, NOS, NICs and workloads before accepting a configuration. [section 15, UNKNOWN validation]

#9.3 The open item

A validated Tomahawk 5 plus ConnectX-8 RoCEv2 lossless profile (PFC, ECN thresholds, buffer profile and DCQCN parameters on the NIC) is UNKNOWN [L Q24]. This is the deciding item for a Mode A backend and the first step of the validation plan (section 15).

9Adaptive routing and load balancing vs Spectrum-X

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Capability NVIDIA Spectrum-X (as the cited docs describe it) Edgecore AIS800 with SONiC Tag
Path balancing End to end with the SuperNIC; in the B300 SuperPOD, ConnectX-8's "onboard plane load balancer unit" plus "NVIDIA Route software" [N1 section 4.1] Tomahawk 5 "Cognitive/Adaptive routing and Dynamic Load Balancing (DLB) and Global Load Balancing (GLB)" [E1] VERIFIED, each from its own docs
NOS exposure Native on Spectrum switches; on Cisco Silicon One it needs an NVIDIA and Cisco licensed feature [C1 "NVIDIA Spectrum-X"] GLB is "Subject to NOS" [E1]; which DLB and GLB modes Broadcom Enterprise SONiC exposes on AIS800 UNKNOWN for Edgecore NOS
Measured behavior DDN claims "up-to +16% over traditional RoCEv2 performance" with an unnamed baseline [N2] Up to 35.6% collective performance improvement at 1:1 with congestion aware packet spraying, on AMD MI300X with Broadcom Thor 2 NICs, not ConnectX [E9] VERIFIED for each source's own test
Packet spray with NIC reorder Part of the Spectrum-X switch plus SuperNIC pairing Not tested on ConnectX-8; the published spray result used Broadcom Thor 2 NICs [E9] UNKNOWN
Congestion control Hardware accelerated, switch plus SuperNIC [N2] ECN plus PFC with DCQCN; "Supports end-to-end congestion control" [E1] VERIFIED feature; tuned profile UNKNOWN
Telemetry NVIDIA NetQ for Spectrum switches running Cumulus [S2; N1 section 4.1] "Programmable in-band telemetry" in silicon [E1]; SONiC streaming telemetry VERIFIED silicon; NOS feature INFERRED

Plain reading: Spectrum-X is a switch plus SuperNIC system. Edgecore offers a different, open load balancing toolset in the switch silicon. Whether it closes the gap for a given workload is a test question, not a datasheet question. Don't claim parity, and don't claim a deficit we haven't measured.

Adaptive routing and load balancing vs Spectrum-X · detailed planning notes

(Mirrors Cisco: "NVIDIA Spectrum-X" [C1, C2].)

Capability NVIDIA Spectrum-X (as the cited docs describe it) Edgecore AIS800 with SONiC Tag
Path balancing in the switch End to end with the SuperNIC; in the B300 SuperPOD, ConnectX-8's "onboard plane load balancer unit" plus "NVIDIA Route software" balance over the best path [N1 section 4.1] Tomahawk 5 "Cognitive/Adaptive routing and Dynamic Load Balancing (DLB) and Global Load Balancing (GLB)" in silicon [E1] VERIFIED (both sides, from their own docs)
NOS exposure Native on Spectrum switches; on Cisco Silicon One requires the FGLB license plus DCN Advantage on NX-OS 10.6(1)F or later [C1 "NVIDIA Spectrum-X"] GLB "subject to NOS" [E1]; which DLB and GLB modes Broadcom Enterprise SONiC exposes on AIS800 UNKNOWN for Edgecore NOS
Measured behavior No comparative result is reproduced in this edition No end to end GPU-cluster result is established here UNKNOWN comparison; section 15
Packet spray with NIC reorder Part of the Spectrum-X switch plus SuperNIC pairing [glossary "Spectrum-X"] ConnectX-8 reorder behavior behind a non Spectrum switch requires validation UNKNOWN
Congestion control Evaluate the selected NVIDIA switch and SuperNIC profile [N1] Datasheet states "Supports end-to-end congestion control" [E1]; selected configuration requires validation VERIFIED feature claim; tuned profile UNKNOWN
Telemetry NVIDIA NetQ [N1 section 4.1] "Programmable in-band telemetry" in silicon [E1]; SONiC streaming telemetry VERIFIED silicon; NOS feature INFERRED
NVIDIA program standing Required in NVIDIA Enterprise RAs; NCP CIN Not documented for Edgecore VERIFIED [S2, S6]

Plain reading. Spectrum-X is a switch plus SuperNIC system. Edgecore offers a different load balancing toolset in the switch silicon [E1]. Whether it meets the requirements of a given workload is a test question. Performance parity or deficit is UNKNOWN without a matched test. [section 15]

Alongside NVIDIA NCP

10Edgecore alongside NVIDIA NCP

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The true sentence for Mode B: NCP's published normative requirements say what the frontend, storage, management and edge networks must do, but the public tables don't name who builds them. The reference tables and one line of IPR prose describe Spectrum for the frontend, and the gated GB300 NVL72 Reference Design decides. So every Mode B deal needs the switch choice confirmed in writing for that build. INFERRED from the sources below.

10.1 Who owns what in a GB300 NVL72 NCP

FIG 5 · MODE B · GB300 NVL72 · NCP COMPANIONNVLCINTANSMN
GPU POD · UP TO 1,152 GPUS [S1]CORE POD [S1]TAN underlay · leaf and spineBGP with IPv4 and EVPN/VPNv4 (IPR NET-5) · overlay terminates on BlueField HBN [S2]EDGECOREDC edge · NVIDIA POPVIF and BGP · MACsecGATED · RD-2NVL72 rack 1NVLink72 GPUsBlueField-3ConnectX-8NVL72 rack 2NVLink72 GPUsBlueField-3ConnectX-8NVL72 rack 16NVLink72 GPUsBlueField-3ConnectX-8• • •CIN · InfiniBand or Spectrum-XIPR NET-2, MUST · NVIDIA owned · rail mapping gatedNVIDIAStorage leavesRDMA, IPR STO-2 MUSTEDGECOREControl nodescontrol planesUtility clusterbootstrapGeneral purposenon GPU computeStorage systemscertified, STO-3Core POD switchingno vendor named in public NCP tablesEDGECORESMN · secure management network · 1GR24 SEC12 dedicated BMC network · SDN04 isolated from tenants · CNP10 Redfish over TLS, no IPMIEDGECOREBlueField-3 to TAN, 2 x 200G per tray
Edgecore suppliesNVIDIA ownedGatedHosts and partner systemsFrontendOOB
Edgecore alongside NVIDIA NCP: NVIDIA owns NVLink, BlueField-3, ConnectX-8 and the CIN (IPR NET-1, NET-2). Edgecore candidates are the TAN underlay, storage leaves, Core POD switching and the SMN. The edge is gated: its appliance rules sit in the reference designs IPR says are access controlled. VERIFIED requirements; INFERRED fit.
  • NVIDIA owned: the NVLink domain and NVLink switch trays [S1], the CIN (InfiniBand or Spectrum-X, IPR NET-2 MUST), BlueField-3 on every tray (IPR NET-1 MUST), ConnectX-8. VERIFIED.
  • Tenant overlay: owned by the BlueField DPU and NVIDIA Infra Controller. The DPU runs "DOCA/HBN to terminate tenant overlays at the edge", and Infra Controller isolates tenants on Ethernet "via HBN". VERIFIED [S2]. So the Edgecore switch is the BGP underlay, not the VTEP. INFERRED.
  • Edgecore candidates: TAN underlay leaf and spine, storage leaves, SMN, and Core POD switching. Border and NVIDIA POP links only where the gated edge appliance rules allow (section 10.4).

10.2 Surfaces with no vendor named in public NCP normative tables

The HGX Enterprise RA, which isn't an NCP document, does name SN5600 for the converged fabric and SN2201 for OOB [S6 Table 5], and the S2 reference table names Spectrum for the TAN.

Network or zone What NVIDIA requires Edgecore role Tag
TAN (frontend) IPR NET-1 BlueField-3 on the host, MUST; NET-5 "BGP is the routing protocol with IPv4 and EVPN/VPNv4 address families", MUST; NET-6 BGP underlay plus EVPN with VXLAN overlay, SHOULD Leaf and spine BGP underlay with the EVPN address family VERIFIED requirement [IPR]; INFERRED role
Storage IPR STO-2 "Deploy storage with RDMA", MUST; STO-3 certified storage platforms, MUST; STO-1 the gated NCP storage reference design, MUST Storage leaves carrying a lossless RoCE class; STO-1 contents UNKNOWN VERIFIED requirement [IPR]; UNKNOWN fit
SMN (OOB) S2 "Ethernet (1GbE)"; R24 SEC12 a dedicated, restricted BMC network; SDN04 OOB interfaces "isolated from all tenant-accessible networks"; CNP10 "Redfish over TLS. IPMI must be disabled." 1G OOB switches with 25G or 100G uplinks VERIFIED [S2; R24]
Core POD Control nodes, general purpose nodes, high speed storage, utility cluster, DC edge cluster [S1] Data center switching for everything outside the GPU POD VERIFIED text; INFERRED fit
DC edge and NVIDIA POP links R24 NET04 and NET05 Private Cloud Interconnect "with VIF and BGP"; NET06 "redundant upstream paths"; SEC18 "MACsec Protection Links" to the NVIDIA POP. IPR: the gated reference designs "also specify the network-appliance requirements for edge connectivity" Border and DCI candidate only. Edge rules are gated, and MACsec isn't on the AIS800-64O datasheet [E1] VERIFIED requirement; UNKNOWN fit

10.3 Obligations every Edgecore switch in an NCP must meet

All VERIFIED as requirements in [R24]. How each is met on Edgecore is INFERRED unless stated.

  • NET01 Backend Switch Fabric API. Per node, the switch path to the core with "a unique, stable identifier" per switch. It "applies to north-south, east-west, and NVLink networks, but not to the management network", so Edgecore TAN switches must appear in it. A "switch" there "may represent a physical switch or a logical connectivity domain".
  • CNP08 Stable Identifiers for "nodes and switches".
  • SDN09 Observability. Tenant visible telemetry on "degraded states, errors, drops, utilization, and latency".
  • Network telemetry across every network domain R24 lists (north south, east west, management, NVSwitch fabric and host network), so the Edgecore switches feed the north south and management parts, delivered within 120 seconds, with "Native OpenTelemetry Protocol delivery" preferred. Switch syslogs and kernel logs are on the required log list.
  • SEC13 "Encryption and mutual authentication for all east-west and north-south network traffic." Where this is enforced (host, DPU or switch) isn't stated. UNKNOWN for the Edgecore role. Don't claim switch encryption.
  • SEC16. The NCP must name its edge enforcement technology "and its specific placement in the packet path".

10.4 Caveats an NVIDIA reviewer will raise

  • IPR prose names NVIDIA switches. "Host networking on the BlueField DPUs and the network appliances, the Spectrum Ethernet switches and Quantum InfiniBand switches, keep tenants isolated end-to-end." The preceding paragraph puts the east west plane on "InfiniBand or Spectrum-X". VERIFIED [IPR "Networking and Multi-tenancy"]. IPR's own tip says prose "does not itself impose requirements". VERIFIED. Acknowledge the sentence; don't hide it.
  • The S2 table names Spectrum for the TAN. VERIFIED [S2]. Our position is "not excluded by public normative text", never "NCP leaves the frontend open".
  • RD-2 is a MUST and it's gated. "Adhere to the GB300 NVL72 Reference Design ... server spec, network cabling." VERIFIED [IPR RD-2]. Its switch rules are UNKNOWN.
  • The edge is gated too. VERIFIED [IPR "Reference Designs"].
  • Management stack. S2 describes NVIDIA's network management as NMX for NVLink, UFM for InfiniBand and "NetQ provides visibility for Spectrum switches running Cumulus". VERIFIED [S2]. A SONiC switch sits outside NetQ, so the NCP's own tooling has to cover it. UNKNOWN how NCPs handle this today (gap G17).
  • Not every back end row is vendor locked, and it's fair to say so. IPR NET-3 (SHOULD, NIXL KV transfer and weight P2P) asks only for an "East-west back-end RDMA fabric", and NET-8 (MUST) says "Label InfiniBand and RoCE accurately". VERIFIED [IPR]. That doesn't open the NCP CIN, because NET-2 still binds it. INFERRED.

10.5 The HGX version: next to the HGX Enterprise RA

Public NCP pages describe NVL72 [S1, IPR]. For HGX B300, the HGX inference profile defers to a gated hardware reference [IRA "Physical Architecture"], so the honest yardstick is the HGX Enterprise RA [S6].

  • The ERA builds every fabric on Spectrum-X switches (SN5600) and OOB on SN2201. VERIFIED [S6 "Spine-Leaf Networking", Table 5]. Replace the converged or OOB switches with Edgecore and the build follows the ERA's topology, not the ERA. INFERRED.
  • Edgecore's frontend counts match NVIDIA's converged fabric counts: 2 switches at 32 nodes, 6 at 64 nodes. NVIDIA's Table 7 shows 2 leaves at 32 nodes, 4 leaves plus 2 spines at 64, and 8 leaves plus 4 spines at 128. VERIFIED [S6 Table 7; E4 slide 3]. NVIDIA's own 64 node page conflicts with Table 7: it says "Cost-efficient converged two-switch fabric" [S6 "64 Nodes"]. We follow Table 7, and the match holds only against Table 7.
  • NVIDIA's bandwidth floors: "minimum 25Gb bandwidth per GPU" to the customer network and "minimum 12.5Gb bandwidth per GPU" for storage. VERIFIED [S6 "32 Nodes"].

10.6 NVL72 frontend and management sizing

All INFERRED arithmetic from [S1] and [E1].

  • TAN demand. 36 x 200G BlueField-3 ports per rack, 576 per 16 rack POD. AIS800-64O ports break out to "4 x 200 GbE" [E1, VERIFIED], so a POD needs 144 switch ports of 4 x 200G, before Core POD and storage. INFERRED (576 / 4). Example at 1:1: 6 frontend leaves as 3 dual homed pairs and 3 to 4 spines per POD. INFERRED.
  • Lane rate. The AIS800-64O supports 4 x 200G on 100G PAM4 lanes and 2 x 200G on 50G PAM4 lanes [E1, VERIFIED]. Which one the BlueField-3 port and optic need is UNKNOWN (gap G18).
  • SMN. At least 18 x 1G per rack from compute trays [S1], so at least 288 per 16 rack POD, at least 6 x 48 port switches before NVLink switch trays, power shelves, cooling and switch management ports. INFERRED.

11Frontend, storage partners and management

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11.1 Frontend (TAN, converged)

32 HGX nodes 64 HGX nodes 256 HGX nodes
Frontend design 2 frontend switches, storage attached to them 2 frontend spines + 2 compute frontend leaves + 2 storage leaves 4 frontend spines + 8 compute frontend leaves (1 pair per 64 nodes) + 2 storage leaves
Frontend and storage AIS800-64O 2 6 14
Compute frontend leaf oversubscription n/a, no spine tier 2:1 (32 ports down as 64 x 400G, 16 x 800G up) 2:1
Storage leaf uplinks n/a 2 x 16 x 800G = 25.6 Tbps 2 x 16 x 800G = 25.6 Tbps
Storage uplink per GPU sized by storage ports 50 Gbps 12.5 Gbps

VERIFIED as design [E4 slides 3, 5 to 9]; per GPU figures INFERRED (25.6 Tbps / GPUs). The 256 node design lands on NVIDIA's "minimum 12.5Gb bandwidth per GPU" for storage [S6], and the 64 node design exceeds it. The deck labels frontend and storage counts as "estimates, before final storage sizing" [E4 slide 3].

Multitenancy on the frontend runs a BGP underlay with BGP EVPN and VXLAN, matching Cisco's VRF model [C2 "Multitenancy"], NVIDIA's SuperPOD Ethernet fabric "segregated with VXLAN and EVPN" [N1 section 4.4], and IPR NET-5 and NET-6. VERIFIED. Where a BlueField DPU terminates the overlay (always in Mode B), the leaf is mostly a BGP underlay router; where the leaf is the VTEP, its EVPN implementation is the product. INFERRED.

FIG 6 · TAN AND STORAGE · 64 AND 256 HGX NODESNVLCINTANSMN
BORDERcustomer edgeFE SPINE2 or 4FE LEAF1 pair / 64 nodesHOSTSBF3 2 x 400GBorder / DCIBGP handover · ZR and ZR+ opticsFE spine 1AIS800-64OFE spine 2AIS800-64OFE leaf A16 x 800G up, 2:1FE leaf B16 x 800G up, 2:1Storage leaf 116 x 800G upStorage leaf 216 x 800G upHGX nodeBF3 2 x 400GHGX nodeBF3 2 x 400GHGX nodeBF3 2 x 400GStorage serverpartner suppliedStorage serverpartner suppliedStorage serverpartner suppliedeach BF3 port to a different leafRoCE class: DSCP 26, CNP 48, PFC q3
Edgecore suppliesNVIDIA ownedServers and partner systemsBackend 800G, shaded by railFrontendOOB 1G
Frontend converged fabric with a dedicated storage leaf pair. Compute leaves run 2:1, storage leaves uplink 16 x 800G each. VERIFIED as design [E4 slides 5, 6].

11.2 Storage

  • Attachment. At 32 HGX nodes storage servers dual home to the two frontend switches; at 64 and 256 nodes to a dedicated storage leaf pair uplinked 16 x 800G each to the frontend spines. VERIFIED as design [E4 slides 4 to 6]. NVIDIA attaches storage at "a 1:1 port to uplink ratio". VERIFIED [N1 section 4.3].
  • RDMA or TCP. For a GB300 NVL72 NCP inference build, storage MUST use RDMA [IPR STO-2], and GPUDirect Storage is a SHOULD [IPR STO-5]. VERIFIED. That means a lossless class on the storage path. Outside an NCP, the storage vendor's tested transport decides.
  • Protocol, not product. Configure the storage path to the RoCEv2 QoS profile Cisco's storage RA requires of any switch: RDMA on DSCP 26, CNP on DSCP 48, PFC on queue 3, CNP on queue 6, no global link level flow control. VERIFIED [C4 p.5].
  • Performance targets. NVIDIA's guideline per 64 node SuperPOD SU: "Good" 80 GBps aggregate read and 40 GBps write, "Better" 250 and 124 GBps. VERIFIED [N1 Table 5.2]. Scale to the node count; the storage system sets the achieved number.
  • Partners. Any storage system with standard Ethernet and RoCEv2 clients. NVIDIA-Certified Storage status for a storage system on an Edgecore fabric: not documented for Edgecore. In Mode B, IPR STO-3 requires certified storage platforms. VERIFIED [IPR STO-3].
  • Storage internal network. Where the storage system needs its own back end, put those ports in a provider only VRF. VERIFIED for Cisco [C2 "Storage Internal network"].

11.3 OOB (SMN)

The v1 draft counted one BMC port per server and two OOB switches at 32 nodes. NVIDIA counts "6x 1Gb/s connections" per HGX B300 server and uses "SN2201 switch for every 2 SUs (4 switches total)" at 32 nodes. VERIFIED [S6 "Enterprise RA Scalable Unit", "32 Nodes"]. Corrected:

32 HGX nodes 64 HGX nodes 256 HGX nodes
Server 1G ports, 6 per server 192 384 1,536
Switch management ports 18 30 110
Storage node BMCs (example) 4 ~8 ~16
Total 1G ports 214 ~422 ~1,662
48 port 1G OOB switches 5 9 35
NVIDIA's count, server ports only [S6] 4 8 (the page says "per SU", which would be 16) not given at 256; 32 at 128 nodes, one per 4 nodes

The per server rate is VERIFIED [S6]; totals and switch counts are INFERRED (ceil(ports / 48)), before PDUs, CDUs and console servers. The Edgecore design deck's 2, 3 and 8 OOB switches [E4 slide 3] are superseded.

  • Switch. EPS201 (AS4630-54TE): 48 x 1G RJ45, 4 x 25G and 2 x 100G uplinks, Trident 3. VERIFIED [E3; E7].
  • Uplinks. NVIDIA scales OOB "using a 25 Gbps or 100 Gbps spine layer". VERIFIED [S6 "Out-of-Band (OOB) Management Network"].
  • BMC protocol. In an NCP build, Redfish over TLS only: "IPMI must be disabled." VERIFIED [R24 CNP10]. Outside an NCP it's still the right default. INFERRED.
  • Isolation. OOB on a dedicated, restricted network reached only through a hardened bastion. VERIFIED [R24 SEC12]. Never tenant reachable [C2 "Multitenancy"; N1 section 4.4.2].
  • Console. Every SONiC switch needs a serial console reachable when its management port isn't, to recover a box stuck in ONIE or a bad upgrade. INFERRED.
FIG 7 · SMN · 32 HGX NODESNVLCINTANSMN
OOB AGGOOB VRFOOB 1G5x EPS201 at 32DEVICESevery rackOOB aggregation, or frontend spine in the OOB VRFbastion access only · R24 SEC12OOB switch 148 x 1G · 25G and 100G upOOB switch 248 x 1G · 25G and 100G upOOB switch 348 x 1G · 25G and 100G upOOB switch 448 x 1G · 25G and 100G upOOB switch 548 x 1G · 25G and 100G upHGX server6 x 1G each [S6]Switch mgmt18 at 32 nodesStorage BMC4 examplePDUs and CDUsnot countedConsole serverserial to every switch214 ports at 32 nodes = 5 x 48 port switches (INFERRED)
Edgecore suppliesNVIDIA ownedServers and partner systemsBackend 800G, shaded by railFrontendOOB 1G
OOB corrected to NVIDIA's 6 x 1G per HGX B300 server [S6]: 214 ports and 5 EPS201 switches at 32 nodes, before PDUs, CDUs and consoles. Totals INFERRED.
Storage partner integration (generic) · detailed planning notes

(Mirrors Cisco: "High-Performance Storage" [C1, C2]; NVIDIA: sections 4.3 and Chapter 5 [N1].)

  • Attachment. At 32 nodes storage servers dual home to the two frontend switches; at 64 and 256 nodes to a dedicated storage leaf pair that uplinks 16 x 800G each to the frontend spines [E4 slides 4 to 6, VERIFIED as design]. NVIDIA attaches storage at "a 1:1 port to uplink ratio" with node side "slightly oversubscribed with a ratio near 4:3" [N1 section 4.3, VERIFIED].
  • Protocol, not product. The cited Cisco EBox storage design uses this RoCEv2 QoS profile: RDMA on DSCP 26, CNP on DSCP 48, PFC on queue 3, CNP on queue 6, no global link level flow control [C4 p.5, VERIFIED]. The selected storage partner must confirm the configuration for its deployment. [INFERRED implementation requirement]
  • Performance targets to size against: NVIDIA's storage guideline per 64 node SU, "Good" 80 GBps aggregate read and 40 GBps write, "Better" 250 and 124 GBps [N1 Table 5.2, VERIFIED]. Scale to the Edgecore node count; the storage system sets the achieved number.
  • Partners. Storage system and client interoperability require validation. Cisco uses VAST on Cisco servers (EBox) and notes "other NVIDIA-Certified storage partners can also be used" [C1, VERIFIED]. NVIDIA-Certified Storage status for the proposed storage system on this Edgecore fabric is UNKNOWN; no acceptance is claimed.
  • Storage internal network. Where the storage system needs its own back end (Cisco EBox uses NIC0 internal, NIC1 client), put the internal ports in a provider only VRF [C2 "Storage Internal network", VERIFIED for Cisco].
  • Optics for storage downlinks are TBD with the storage vendor [E4 slides 8, 9].
Operate

12SONiC software and NOS options

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Item Detail Tag and source
Installer Every AIS800 ships with ONIE "for automated loading of compatible open source and commercial NOS offerings" VERIFIED [E1, E2]
Lead NOS Broadcom Enterprise SONiC, one subscription per switch VERIFIED as offer [E4 BOM slides 7 to 9; Edgecore NOS offer as of 2026-09-26]
Alternative NOS Edgecore custom community SONiC development with Edgecore enterprise support and maintenance VERIFIED as offer [Edgecore NOS offer as of 2026-09-26]
Discontinued EC SONiC and its S-SONIC SKUs, since 2026-09-26 VERIFIED [Edgecore NOS offer as of 2026-09-26]
Feature set used here BGP underlay, BGP EVPN with VXLAN, VRF, PFC, ECN, PFC watchdog, ECMP, LAG or EVPN multihoming, streaming telemetry INFERRED (standard SONiC features); per release confirmation needed, gap G6
Silicon features that need NOS support VxLAN RIOT, SRv6 and GLB, "Subject to NOS" VERIFIED [E1 "Performance"]
Switch platform Intel Xeon D-1713NTE, 32 GB ECC, 240 GB NVMe, TPM 2.0, AST2600 BMC with OpenBMC and AST1060 root of trust VERIFIED [E1 "Key Components"]
Timing SyncE and IEEE 1588v2 PTP, 1PPS, 10 MHz and ToD ports VERIFIED [E1]

Host side software (NVIDIA AI Enterprise, drivers, NCCL, Dynamo) is unchanged by the switch choice. INFERRED.

SONiC software and NOS options · detailed planning notes

(Mirrors Cisco: "Software" and the NX-OS references [C1].)

Item Detail Tag and source
Installer Every AIS800 ships with ONIE, "for automated loading of compatible open source and commercial NOS offerings" VERIFIED [E1, E2]
Lead NOS Broadcom Enterprise SONiC, one subscription per switch VERIFIED as offer [E4 BOM slides 7 to 9; repo NOS policy 2026-09-26]
Alternative NOS Edgecore custom community SONiC development with Edgecore enterprise support and maintenance VERIFIED as offer [repo NOS policy 2026-09-26; E4 BOM wording "Edgecore professional services for SONiC"]
Discontinued EC SONiC and its S-SONIC SKUs (since 2026-09-26) VERIFIED [repo]
Feature set for this RA BGP underlay, BGP EVPN with VXLAN, VRF, PFC, ECN, PFC watchdog, ECMP, LAG or EVPN multihoming, streaming telemetry INFERRED (standard SONiC features); per NOS release confirmation needed, Gaps G6
Silicon features needing NOS support VxLAN RIOT, SRv6, GLB: "Subject to NOS" VERIFIED [E1 "Performance"]
Switch platform hardware Intel Xeon D-1713NTE, 32 GB ECC, 240 GB NVMe, TPM 2.0, AST2600 BMC with OpenBMC and AST1060 root of trust VERIFIED [E1 "Key Components"]
Timing SyncE and IEEE 1588v2 PTP, 1PPS, 10 MHz and ToD ports VERIFIED [E1]

Host software may remain NVIDIA-based, but transport settings, plugins, NIC firmware and support profiles require validation with the selected switch/NOS combination. Cisco lists NVIDIA AI Enterprise as part of its RA [C1 "NVIDIA AI Enterprise"]; for Edgecore that is not applicable.

13Automation, day 2 operations and telemetry

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  • Controller. An Edgecore fabric controller for AI fabrics isn't documented. Operate with open tooling: ONIE plus zero touch provisioning, configuration as code, and the NOS's own APIs. INFERRED.
  • Day 0: ONIE install, ZTP, BGP unnumbered underlay per rail leaf, cabling checked against the rail map with LLDP. INFERRED.
  • Day 1: QoS and lossless profile (section 8), EVPN tenants on the frontend (section 14), OOB VRF.
  • Day 2 telemetry: per queue ECN marks, PFC pause counters, buffer occupancy, link errors, optics DOM, and DLB or ECMP member load. Silicon support: "Programmable in-band telemetry" [E1, VERIFIED]; export by streaming telemetry from the NOS INFERRED.
  • For Mode B, map every counter above into R24's network telemetry delivery (within 120 seconds, OpenTelemetry preferred) and NET01 fabric API (section 10.3). VERIFIED as requirement [R24].
  • Resilience: "Hardware-based link failover for network resiliency and reduced job completion time"; hot swap redundant 3000 W PSUs and 7+1 fans. VERIFIED [E1].
Automation, day 2 operations and telemetry · detailed planning notes

(Mirrors Cisco: "Network controller", "Observability" [C1].)

  • Controller. Cisco provisions with Nexus Dashboard (Insights, Orchestrator, Fabric Controller) and also supports Ansible, Chef and Puppet [C1 "Network controller", VERIFIED]. Edgecore publicly describes an Open Fabric controller [E7]. Its release-specific support for this design is UNKNOWN; no controller has been selected or validated here. Operate with open tooling: ONIE plus zero touch provisioning, configuration as code (Ansible, or SONiC config database pushed from Git), and the NOS's own management APIs. INFERRED.
  • Day 0: ONIE install, ZTP, BGP unnumbered underlay per rail leaf, cabling validation against the rail map (LLDP neighbor checks). INFERRED.
  • Day 1: QoS and lossless profile (section 9), EVPN tenants on the frontend (section 14), OOB VRF.
  • Day 2 telemetry: per queue ECN marks, PFC pause counters, buffer occupancy, link errors (FEC, CRC), optics DOM, and DLB or ECMP member load. Silicon support: "Programmable in-band telemetry" [E1, VERIFIED]; export by streaming telemetry from the NOS INFERRED. Cisco flags congestion, bit errors and bursts as anomalies automatically [C1 Introduction]; a comparable Edgecore anomaly engine is not documented.
  • Resilience features: "Hardware-based link failover for network resiliency and reduced job completion time" [E1, VERIFIED]; hot swap redundant 3000 W PSUs and 7+1 fans on AIS800-64O [E1, VERIFIED].
  • Observability platform: Cisco names Splunk [C1 "Observability"]. Edgecore names none; any collector that ingests gNMI or similar streaming telemetry fits. INFERRED.

14Security and multitenancy

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VRF plan, mirroring Cisco's [C2 "Multitenancy"]:

VRF Members Tenant access
vrfOOBMgmt BMC, DPU and SuperNIC BMCs, host management, switch management Never
vrfStorageInternal Storage system internal ports Never
vrf<Tenant>Frontend Tenant node frontend ports, tenant storage VNI, tenant management nodes That tenant
vrf<Tenant>Backend Tenant's backend ports That tenant, Open Ethernet with Edgecore only
  • Backend tenancy in Mode A. Allocate tenants by whole rail blocks where possible: Cisco notes rail grouping "avoids one tenant's excessive resource usage from degrading another". VERIFIED [C2]. EVPN VXLAN on the RoCE backend with Tomahawk 5 and SONiC: performance and lossless behavior UNKNOWN (gap G6).
  • Tenant isolation in Mode B. R24 SDN04: "One tenant shall not be accessible to or observable by another tenant." SEC11 requires hard physical or logical isolation. VERIFIED [R24]. The BlueField DPU enforces it on the host [IPR NET-1]; the Edgecore leaf carries the underlay and EVPN.
  • Platform security. AST1060 root of trust securing OpenBMC; TPM 2.0. VERIFIED [E1]. Edgecore supplies no firewall or host security product; those are customer choices.
  • Encryption. R24 SEC13 and SEC18 (section 10.3). MACsec on AIS800 UNKNOWN (gap G15).
Security and multitenancy · detailed planning notes

Additional v2.4 requirements. CNP10, SDN04, SEC12/13/18/22 and NET01/02 require implementation evidence beyond BGP/EVPN. The available EPS201 datasheet lists TPM 1.2; resolve revision and SEC22 applicability before a compliance claim. Telemetry delivery and secure management also need acceptance tests. [S4; VERIFIED requirements, UNKNOWN implementation]

(Mirrors Cisco: "Multitenancy", "Security" [C2, C1]; NCP NET-5, NET-6 [S3].)

#14.1 Frontend multitenancy (both modes)

The frontend runs a BGP underlay with BGP EVPN control plane and VXLAN data plane. This matches Cisco ("VXLAN data-plane and BGP EVPN control-plane enabling native support for multitenancy") [C2, VERIFIED], NVIDIA's SuperPOD Ethernet fabric "segregated with VXLAN and EVPN" [N1 section 4.4, VERIFIED], and NCP NET-5 (BGP with EVPN, MUST) and NET-6 (EVPN VXLAN multitenancy, SHOULD) [S3, VERIFIED]. On AIS800, VXLAN switching and routing are a datasheet application [E1 "High-Performance Computing", VERIFIED]; the EVPN feature set depends on the NOS (Gaps G6).

VRF plan, mirroring Cisco's [C2 "Multitenancy"]:

VRF Members Tenant access
vrfOOBMgmt BMC, DPU BMC, host management, switch management Never
vrfStorageInternal Storage system internal ports Never
vrf<Tenant>Frontend Tenant node frontend ports, tenant storage VLAN or VNI, tenant management nodes That tenant
vrf<Tenant>Backend Tenant's backend ports That tenant (Open Ethernet with Edgecore only)

In Mode B the BlueField-3 DPU terminates tenant overlays on the host side as NCP NET-1 requires [S3, VERIFIED]; the Edgecore leaf carries the underlay and EVPN.

#14.2 Backend multitenancy (Mode A)

Allocate tenants by whole SUs where possible: Cisco notes rail grouping per SU "makes it efficient in allocating resources in a multi-tenant environment. It avoids one tenant's excessive resource usage from degrading another" [C2, VERIFIED]. For tenants below SU size, isolate by VRF on the backend leaves. Running EVPN VXLAN on the RoCE backend (as Cisco does) on Tomahawk 5 with SONiC: performance and lossless behavior UNKNOWN (Gaps G6).

#14.3 Platform security

  • Hardware root of trust: AST1060 securing OpenBMC; TPM 2.0 [E1, VERIFIED].
  • OOB physically separate and never tenant reachable [C2; N1 section 4.4.2: "no use-case where a non-privileged user needs direct access"].
  • Cisco lists its security portfolio (Secure Firewall, Isovalent, Hypershield, AI Defense) as available but "beyond the scope" of its RA [C1 "Security", VERIFIED]. Edgecore supplies no security product; firewalls and host security are customer choices.
Prove and buy

15Validation and delivery evidence

NVLCINTANSMN
403

Cisco reports end to end testing with "HPC Benchmark, IB PerfTest, NCCL Test, MLCommons Training, and Inference benchmarks". VERIFIED [C1, C2]. Edgecore has no equivalent end to end result for this design. The plan below borrows NVIDIA's own acceptance list so the results speak NVIDIA's language. Every IPR row cited here is a SHOULD, not a MUST. VERIFIED [IPR HW-1 to HW-5].

# Test NVIDIA reference Tool Pass criterion
1 Lossless profile bring up, Tomahawk 5 plus ConnectX-8 none perftest, switch counters Zero drops on the RDMA class; PFC and ECN counters behave as designed
2 RDMA on every rail, same rail and cross rail IPR HW-2: "IB/RoCE rail tests using ib_write_bw on every rail, with loss and error counters clean" ib_write_bw, ib_read_bw, ib_send_lat Near line rate per port; outliers identified
3 Collectives at one rail block or rack, then full cluster IPR HW-1: "NCCL throughput benchmarks using nccl-tests reach SKU performance baselines" nccl-tests all_reduce, all_gather, reduce_scatter, alltoall, with and without PXN Bus bandwidth vs message size recorded; targets set with the customer. Don't quote NVIDIA's numbers as ours
4 GPUDirect RDMA and Storage IPR HW-3 GDS tools, fio Smoke tests pass; storage throughput against N1 Table 5.2, scaled
5 24 hour soak under inference load IPR HW-5: "24-hour soak under representative inference load at a sustained power cap" Customer workload, AIPerf No link flaps, no PFC storms, clean counters
6 Load balancing modes none nccl-tests: fixed hash vs DLB flowlet vs any NOS supported spray Pick the mode with the best job completion time
7 Incast and congestion none many to one perftest, all to all No PFC storms; ECN thresholds tuned
8 Failure: link, optic, leaf, spine, PSU, fan none Pull tests during nccl-tests Job continues; bandwidth drop and recovery time recorded
9 PFC deadlock and watchdog none Induced pause storm Watchdog clears; no fabric wide stall
10 Frontend tenancy R24 SDN04 EVPN tenant create, delete, cross tenant reachability No cross tenant reachability
11 Inference data movement IPR NET-3, KUB-38 NIXL KV transfer and weight pull Cold node hydration time recorded against the 60 s target

Existing public Edgecore evidence: the AIS800-64O collective communication benchmark on AMD MI300X with Broadcom Thor 2 NICs, up to 35.6% improvement at 1:1 and 26.7% at 2:1 with congestion aware packet spraying [E9]. It used AMD GPUs and Broadcom NICs, not ConnectX-8 or NCCL on B300, so it informs this plan and doesn't replace any test in it. VERIFIED [E9].

Validation and test plan · detailed planning notes

Public review boundary. Restricted test results are omitted. This edition contains a validation plan and does not establish completed validation of this GPU cluster. [UNKNOWN acceptance; test plan below]

(Mirrors Cisco: "Testing and certification" [C1, C2].)

Cisco reports solution testing with compute, storage and availability benchmarks [C1, C2, VERIFIED for Cisco]. This design has no equivalent end to end result established in this public edition. UNKNOWN: acceptance of the proposed Edgecore configuration.

#Plan (to run per deployment or as an Edgecore lab validation)

# Test Tool Pass criterion
1 Lossless profile bring up, TH5 plus ConnectX-8 perftest, switch counters Zero drops on the RDMA class, PFC and ECN counters behave as designed. Target values UNKNOWN until set with the customer
2 Point to point RDMA bandwidth and latency, same rail (1 hop) and cross rail (3 hops) perftest: ib_write_bw, ib_read_bw, ib_send_lat, ib_write_lat Near line rate per 400G port; latency recorded. Thresholds TBD
3 Collectives at 1 SU, then full cluster nccl-tests: all_reduce_perf, all_gather_perf, reduce_scatter_perf, alltoall_perf, with and without PXN Bus bandwidth recorded vs message size; targets TBD with customer. Do not quote NVIDIA's numbers as ours
4 Load balancing modes nccl-tests, fixed hash vs DLB flowlet vs any NOS supported spray Pick the mode with the best job completion time
5 Incast and congestion many to one perftest, all to all No PFC storms; determine ECN thresholds and record workload behavior
6 Storage throughput fio and GPUDirect Storage tools, from all nodes Against N1 Table 5.2 Good or Better, scaled
7 Failure: link, optic, leaf, spine, PSU, fan Pull tests during nccl-tests Record disruption, bandwidth loss and recovery/restart time against workload criteria. Leaf loss can disconnect singly attached rails. Measure the actual result
8 PFC deadlock and watchdog Induced pause storm Watchdog clears; no fabric wide stall
9 Frontend tenancy EVPN tenant create, delete, cross tenant reachability test No cross tenant reachability
10 Day 2 telemetry Collector Every counter in section 12 visible

16BOM structure (no prices)

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250

Model numbers from datasheets [E1, E3]; optics part numbers from the design deck [E4]; HGX quantities from [E4] slides 7 to 9; OOB from section 11.3.

Line Model Description 32 HGX nodes 64 HGX nodes 256 HGX nodes
Backend leaf AIS800-64O-AF 64 x OSFP800, Tomahawk 5, rail leaf 8 16 64
Backend spine AIS800-64O-AF Spine 8 8 32
Frontend spine AIS800-64O-AF None at 32 nodes 0 2 4
Frontend leaf AIS800-64O-AF Frontend switch at 32 nodes 2 2 8
Storage leaf AIS800-64O-AF Storage leaf pair 0 2 2
AIS800-64O total 18 30 110
NOS Broadcom Enterprise SONiC, or Edgecore custom SONiC with Edgecore support 1 per switch 18 + OOB 30 + OOB 110 + OOB
OOB EPS201 (AS4630-54TE) 48 x 1G 5 9 35
Optics ET8001-2DR4 OSFP 800G 2xDR4 1,088 2,240 8,768
Optics ET7512-DR4 QSFP112 400G DR4, frontend card side 64 128 512
Cabling MPO fiber; Cat6 for OOB per rack layout TBD TBD TBD

Edgecore alongside NCP on HGX removes the backend leaf, spine and backend optics lines. INFERRED. A GB300 NVL72 BOM follows the section 6.2 counts (for example 54 AIS800-64O for one 16 rack POD backend in Mode A) and is INFERRED until a customer rack plan exists. The AIS800-32O (32 x OSFP800, Tomahawk 5, 25.6 Tbps, 1RU) [E2, VERIFIED] fits roles needing 32 ports or fewer, such as a storage leaf. INFERRED.

BOM structure (no prices) · detailed planning notes

(Mirrors Cisco: "Cluster BOM" Tables 5 and 6 [C1].)

Model numbers from datasheets [E1, E3]; optics part numbers from the Edgecore design deck [E4]; quantities from [E4] slides 7 to 9. Choose AF (front to back) or AB (back to front) airflow and AC or DC power per site [E1 "Ordering Information"].

Line Model Description 32 nodes 64 nodes 256 nodes
Backend leaf AIS800-64O-AF 64 x OSFP800, Tomahawk 5, rail leaf 8 16 64
Backend spine AIS800-64O-AF Spine 8 8 32
Frontend spine AIS800-64O-AF Frontend spine (none at 32 nodes) 0 2 4
Frontend leaf AIS800-64O-AF Compute frontend leaf (frontend switch at 32 nodes) 2 2 8
Storage leaf AIS800-64O-AF Storage leaf pair 0 2 2
AIS800-64O total 18 30 110
NOS Broadcom Enterprise SONiC, or Edgecore custom SONiC with Edgecore support 1 per switch, term per quote 18 + OOB 30 + OOB 110 + OOB
OOB EPS201 (datasheet) or AS4630-54T (generic deck) 48 x 1G at least 5* at least 9* at least 35*
Optics ET8001-2DR4 OSFP 800G 2xDR4 1,088 2,240 8,768
Optics ET7512-DR4 QSFP112 400G DR4, frontend card side 64 128 512
Storage downlink optics TBD per storage vendor included above TBD TBD
Cabling MPO fiber; Cat6 for OOB per rack layout TBD TBD TBD
Hardware support Advance replacement or standard warranty per quote per switch per switch per switch

Mode B BOM, as a proposed switch-placement comparison only, removes the backend leaf and backend spine lines and the backend optics (1,024 / 2,048 / 8,192 ET8001-2DR4), leaving 2, 6 or 14 candidate AIS800-64O switches plus a separately re-sized OOB network. Retained NVIDIA backend switches still consume management ports. INFERRED from [E4].

Optional model: the AIS800-32O (32 x OSFP800, BCM78902 Tomahawk 5, 25.6 Tbps, 1RU, up to 160 logical ports) [E2, VERIFIED] fits roles needing 32 ports or fewer, such as a storage leaf (16 down, 16 up). Not used in the baseline to keep one switch model. INFERRED.

17Compliance matrix

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"Meets" means the Edgecore design provides the element. It doesn't mean NVIDIA has certified anything.

# Requirement (source) Open Ethernet with Edgecore Alongside NVIDIA NCP Tag
1 HGX B300 node: 8 ConnectX-8 east west, BlueField-3 B3240 north south [S6 Table 5] Meets Meets VERIFIED
2 ConnectX-8 at 2 x 400G per GPU [S6 Table 5] Meets (800G per GPU) NVIDIA owned VERIFIED
3 Rail optimized, 1:1 east west leaf spine [S6; N1 4.1] Meets n/a (NVIDIA) VERIFIED design
4 Dual plane in NVIDIA's HGX design [S6] Option (5.5); baseline single plane n/a INFERRED
5 East west on InfiniBand or Spectrum-X for GB300 NCP inference builds [IPR NET-2, MUST] Not met by design (Mode A is non NCP) Met by NVIDIA's fabric; Edgecore excluded VERIFIED
6 RDMA east west fabric for NIXL KV transfer [IPR NET-3, SHOULD] Meets in design; NIXL performance UNKNOWN NVIDIA owned VERIFIED requirement
7 Accurate IB and RoCE labeling to NCCL [IPR NET-8, MUST] Host side, RoCE NVIDIA owned VERIFIED requirement
8 North south through BlueField-3 [IPR NET-1, MUST] Optional Meets (host side) VERIFIED
9 BGP with IPv4 and EVPN/VPNv4 [IPR NET-5, MUST] Meets (NOS dependent) Meets (NOS dependent) INFERRED
10 BGP underlay, EVPN, VXLAN multitenancy [IPR NET-6, SHOULD] Meets frontend; backend UNKNOWN Meets frontend underlay INFERRED / UNKNOWN
11 Adhere to the GB300 NVL72 Reference Design [IPR RD-2, MUST] n/a UNKNOWN (gated) UNKNOWN
12 Storage with RDMA [IPR STO-2, MUST]; certified storage platforms [STO-3, MUST] Configurable Lossless class on storage leaves; certification is the storage vendor's VERIFIED requirement
13 TAN named "Ethernet (Spectrum)" in the NCP reference table [S2] n/a Not excluded by public normative text; not Spectrum INFERRED
14 Backend Switch Fabric API visibility [R24 NET01] n/a Switch topology must be exposed; implementation by the NCP's tooling INFERRED
15 Stable switch identifiers [R24 CNP08] Meets (serials) Meets (serials) INFERRED
16 Network observability [R24 SDN09]; telemetry within 120 s [R24 "Telemetry"] Open tooling Export path needed INFERRED
17 Redfish over TLS, IPMI disabled [R24 CNP10] Recommended Required on node BMCs VERIFIED requirement
18 BMC on a dedicated restricted network [R24 SEC12]; OOB isolated from tenants [R24 SDN04] Meets Meets VERIFIED requirement, INFERRED design
19 Encryption and mutual authentication for all east west and north south traffic [R24 SEC13] UNKNOWN UNKNOWN UNKNOWN
20 MACsec on links to the NVIDIA POP [R24 SEC18] n/a UNKNOWN for AIS800 UNKNOWN
21 Storage bandwidth floor of 12.5 Gb per GPU [S6] Meets at 64 and 256 nodes Same INFERRED
22 OOB on 1G with 25G or 100G uplinks [S6] Meets (EPS201) Meets VERIFIED
23 Customer edge: at least 2 x 100GbE, BGP handover [N1 4.4.2.1] Meets (8 x 100G breakout) Gated edge rules VERIFIED breakout [E1]
24 DCI 400G ZR and OpenZR+, 800G ZR and ZR+ per datasheet Gated edge rules VERIFIED [E1 "Cloud DCI"]
25 Validated Tomahawk 5 plus ConnectX-8 lossless profile UNKNOWN n/a UNKNOWN
26 End to end tests: NCCL, perftest, soak [IPR HW-1, HW-2, HW-5, SHOULD] Plan only Plan only VERIFIED partial evidence
27 NVIDIA Enterprise RA or NCP label Not claimed NCP status depends on NVIDIA's fabric and approval, not Edgecore VERIFIED
Compliance matrix · detailed planning notes

Rows are Cisco and NVIDIA RA requirements. "Proposed" means the design intends to provide the element. It is not a test result or NVIDIA acceptance verdict. Evidence tags qualify only the cited statement.

# Requirement (source) Open Ethernet with Edgecore Alongside NVIDIA NCP Tag Source for our answer
1 HGX B300 node: 8x CX-8 east west, 1 to 2 BF3 B3240 north south [C1 App. A; S6 Table 5] Proposed; exact OEM profile required Proposed VERIFIED S6 Table 5
2 CX-8 at 2 x 400G per GPU [S6 Table 5; C1] Proposed (800G per GPU) NVIDIA owned VERIFIED E4 slide 4; E1 port modes
3 Rail optimized east west leaf spine [S6; C1; N1 4.1] Proposed n/a (NVIDIA) VERIFIED design E4
4 Dual plane recommended [C1; N1 4.1] Option (6.6); baseline single plane n/a INFERRED section 6.6
5 1:1 nonblocking east west [C1 tables; N1 Table 3.1] Proposed n/a VERIFIED design E4 slide 3
6 SU based growth, cable the full SU [N1 Ch.4; C2] Proposed (32 node SU) n/a VERIFIED design E4
7 Super spine beyond two tier [C2] Proposed by design rule (section 8) n/a INFERRED E1 arithmetic
8 East west on Spectrum-X or InfiniBand for NCP compliance [S2; S3 NET-2; C2] Not met by design (Mode A is non NCP) Prescribed compute fabric retained; full acceptance separate VERIFIED S2, S3, S4
9 Spectrum-X features on the compute fabric [C1; N1] Spectrum-X integration not claimed; TH5 feature exposure needs NOS proof NVIDIA owned VERIFIED E1; C1
10 GB300 provider north south via BlueField-3 DPU [S3 NET-1] Optional (DPU or NIC) Proposed (host side) VERIFIED S3
11 Converged north south, 2 x 400G dual homed per node [C1] Proposed Proposed VERIFIED design E4
12 Storage bandwidth reserve, 12.5 Gbps per GPU [C1] Proposed at 64 and 256 nodes; 32 nodes per storage sizing Same INFERRED section 6.2
13 Frontend switch named "Ethernet (Spectrum)" in NCP table [S2] n/a Proposed substitution; acceptance UNKNOWN INFERRED L Q18
14 BGP with EVPN [S3 NET-5] Proposed (NOS dependent) Proposed (NOS dependent) INFERRED section 14
15 EVPN VXLAN multitenancy [S3 NET-6; C2] Proposed frontend; backend UNKNOWN Proposed frontend INFERRED / UNKNOWN section 14
16 Tenant VRF model incl. OOB and storage internal VRFs [C2] Proposed Proposed INFERRED section 14
17 Lossless RoCEv2 QoS: DSCP 26, CNP 48, PFC q3 [C4] Proposed (configurable) Proposed (storage) VERIFIED cited storage profile, INFERRED application C4
18 Validated TH5 plus CX-8 lossless profile UNKNOWN n/a UNKNOWN L Q24
19 OOB on separate 1G network, BMC, DPU BMC, switch mgmt, PDU [C1; C2; N1 4.4.2] Proposed 1G; 10G host mgmt not in generic design Same VERIFIED / gap E3; E4
20 OOB switch vendor [S1; S2] Edgecore Edgecore candidate; acceptance UNKNOWN VERIFIED text, INFERRED proposal; UNKNOWN acceptance L Q16
21 Customer edge: at least 2 x 100GbE DR1, BGP handover [N1 4.4.2.1] Proposed (AIS800 ports break out to 8 x 100G, 1 lane 100G PAM4) Proposed INFERRED E1 port modes
22 Border leaf, L3 routing, VXLAN terminated inside fabric [C2] Proposed Proposed INFERRED E1
23 DCI AIS800 supports 400G QSFP-DD ZR, OpenZR+ and 800G OSFP ZR, ZR+ per datasheet Same VERIFIED E1 "Cloud DCI"
24 Network controller with telemetry and anomaly detection [C1] Open Fabric controller documented; support for this design UNKNOWN Same UNKNOWN release-specific validation section 12; E7
25 Observability platform [C1] Customer choice Same INFERRED section 12
26 Security portfolio [C1] Platform RoT, TPM; no Edgecore security product Same VERIFIED platform E1
27 NVIDIA-Certified systems [C1] Servers are NVIDIA's or OEM's Same n/a to switches C1
28 NVIDIA-Certified storage at NCP level [C1; C2] Not documented for this Edgecore design Not documented for this Edgecore design UNKNOWN section 13
29 End to end tests: NCCL, perftest, HPC, MLPerf, HA [C1; C2] Plan only Plan only UNKNOWN completed validation section 15
30 NVIDIA Enterprise RA or NCP label Not claimed NCP acceptance requires the complete applicable deployment requirements; Edgecore substitutions remain UNKNOWN VERIFIED S4; S6; L Q1
31 NVIDIA AI Enterprise, NIM [C1] Exact transport configuration and support require validation Same n/a C1
32 Optics table incl. NIC side form factor [C1 Table 1] Part numbers known; specs and CX-8 fit UNKNOWN Frontend only UNKNOWN E4

18Gaps and open items

ID Gap Why it matters What settles it
G1 Validated Tomahawk 5 plus ConnectX-8 RoCEv2 lossless profile Deciding item for Open Ethernet with Edgecore on both platforms Edgecore lab report with real ConnectX-8 [L Q24]
G2 No end to end NCCL, perftest, NIXL or storage results on AIS800 with B300 We publish a plan, not results Lab run of section 15
G3 ConnectX-8 multi plane load balancer, packet spray and reorder behind a non NVIDIA switch Dual plane value and the spray option NVIDIA statement or lab test [L Q12]
G4 No Edgecore transceiver datasheet in the library; NIC side heat sink type and ConnectX-8 interop for ET8001-2DR4; ET7512-DR4 with BlueField-3 Wrong optic means no link Optics datasheets and an interop list
G5 OOB model: the product page lists EPS201 as AS4630-54TE [E7]; the design deck says AS4630-54T 54T and 54TE may be different SKUs PLM confirmation
G6 NOS feature confirmation on AIS800: DLB and GLB modes, EVPN VXLAN, PFC watchdog, telemetry, EVPN on the RoCE backend Sections 9, 12, 14 rest on it NOS release notes or PLM
G7 Host management ports at 10G (Cisco cables 2 per node) A 10GBASE-T switch line may be needed Customer server spec
G8 Design deck inconsistencies on NIC form factors Optic and cage choice Customer's B300 server spec; this RA follows S6
G9 Frontend and storage counts are estimates before storage sizing [E4] BOM at 64 and 256 Storage vendor sizing
G10 Mode B frontend acceptance: public text names Spectrum for the TAN; the gated reference design wasn't read Mode B sales claim NVIDIA approval in writing for the specific build
G11 Half closed: NVIDIA's HGX ERA SU is 4 nodes [S6]. Still open: whether NVIDIA's converged switch counts in Tables 7 and 9 agree Side by side with NVIDIA's ERA Re read S6 Table 9
G12 Two tier ceiling: 256 HGX nodes or 28 NVL72 racks leave no free spine ports Growth needs a rebuild unless planned Choose dual plane or three tier at design time
G13 Link failure impact on the CIN under load Resilience claims Failure tests, section 15 test 8
G14 No NVIDIA certification, validation or partnership for Edgecore in this design A procurement checkbox at some buyers None claimed; state it plainly
G15 MACsec on AIS800 isn't on the datasheet R24 SEC18 links to the NVIDIA POP Datasheet or PLM
G16 NVL72 rail mapping of the 72 ConnectX-8 ports per rack Cabling plan for Open Ethernet with Edgecore on NVL72 GB300 NVL72 Reference Design (gated) or customer design
G17 SONiC switches in an NCP's management stack (NetQ is for Cumulus) Mode B operations NCP conversation
G18 BlueField-3 200G port lane rate and optic against AIS800 4 x 200G or 2 x 200G breakout NVL72 frontend links Optics interop test
G19 NVL72 per rack management port count beyond compute trays SMN sizing on NVL72 GB300 NVL72 Reference Design or OEM rack spec
Gaps and open items · detailed planning notes
ID Gap Why it matters What settles it
G1 Validated TH5 plus ConnectX-8 RoCEv2 lossless profile (PFC, ECN, buffers, DCQCN) Deciding item for Mode A backend Edgecore SE or PLM lab report with real CX-8 [L Q24]
G2 No end to end NCCL, perftest or storage results on AIS800 with B300 Cisco publishes tested claims; we publish a plan Lab run of section 15
G3 ConnectX-8 multi plane load balancer, packet spray and reorder behind a non NVIDIA switch Determines dual plane value and spray option NVIDIA statement or lab test; ledger lists CX-9 to non Spectrum as UNKNOWN [L Q12]
G4 Optics: no Edgecore transceiver datasheet in the library; NIC side heat sink type and CX-8 interop for ET8001-2DR4; ET7512-DR4 with BF3 Wrong optic means no link Edgecore optics datasheets and an interop list
G5 OOB model: generic deck names AS4630-54T, which has no datasheet in the library; this RA uses EPS201 (datasheet). Whether they are the same hardware BOM accuracy PLM confirmation [L Q9 lists the EPS201 mapping as unverified]
G6 NOS feature confirmation on AIS800 for Broadcom Enterprise SONiC and custom SONiC: DLB and GLB modes, EVPN VXLAN, PFC watchdog, telemetry, EVPN on the RoCE backend Sections 10, 11, 14 rest on it NOS release notes or PLM
G7 Actual OEM management interfaces and rack distribution remain unconfirmed; six-port planning assumption is not a final cable schedule Add all infrastructure and reserve to section 6.3; required 10G interfaces need 10GBASE-T ports Customer server spec; add a host management switch line
G8 Generic deck internal inconsistencies: slide 2 says CX-8 "2x 400G (QSFP112)" and frontend "CX7 or BF4"; drawings say CX-8 OSFP and "CX7/BF3"; slide 11 lists CX-8 C8180 as OSFP Optic and cage choice Read the customer's B300 server spec; this RA follows S6 and C1 (CX-8 OSFP, 2 x 400G; BF3 B3240 frontend)
G9 Frontend and storage counts are estimates before storage sizing [E4] BOM at 64 and 256 Storage vendor sizing
G10 Mode B frontend acceptance on an NCP build: public text names Spectrum for TAN; gated NCP Hardware Reference Design not read Mode B sales claim NVIDIA SE in writing for the specific build [L Q18]
G11 S6 defines a four-server HGX unit; reconcile version-specific converged switch totals before comparison Side by side with NVIDIA's own ERA Re read S6 [L Q7, Q22]
G12 This flat two-tier 256-node design has no free spine ports; other topology choices have different bounds Growth beyond 256 nodes needs rebuild unless planned Choose dual plane or three tier at design time (section 8)
G13 Link failure impact has not been established for this proposed cluster Resilience claims Failure tests, section 15 test 7
G14 No NVIDIA certification, validation or partnership for Edgecore in this design Procurement checkbox at some buyers None claimed; state it plainly

19References

NVIDIA (all fetched 2026-11-03 unless noted)

Cisco

  • [C1] Cisco N9000 Enterprise RA, "Full Stack AI Infrastructure compliant with NVIDIA HGX B300 Enterprise Reference Architecture", read 2026-08-26. Available from Edgecore on request. Request this document ↗
  • [C2] Cisco N9000 Cloud RA with HGX H200 (Cisco NCP compliant Cloud Reference Architecture), read 2026-08-26. Available from Edgecore on request. Request this document ↗
  • [C4] Cisco EBox NCP HGX High Performance Storage RA, 2026, p.5. Available from Edgecore on request. Request this document ↗

Edgecore

Open questions

  • [L Qn] Edgecore's open question register for this design, 2026-10-30, entry Qn.

Source access: linked NVIDIA and Edgecore pages are public. Other named supporting documents are available on request where distribution is permitted. A VERIFIED tag records what the cited source states, not independent qualification of this proposed deployment.