OcNOS 6.6.1 Available Now: Full AI Fabric on Tomahawk 5, SR Enhancements, and EVPN Expansion

OcNOS 6.6.1 is now generally available. This release delivers the complete AI fabric solution on Broadcom Tomahawk 5-based open hardware — building on the PFC and ETS foundations introduced in OcNOS 6.6 to provide a production-ready lossless RoCEv2 fabric for AI/ML GPU clusters. Service provider deployments benefit from additional Segment Routing enhancements and expanded EVPN coverage.

Complete AI Fabric on Broadcom Tomahawk 5

OcNOS 6.6.1 DC delivers full lossless AI fabric support on Tomahawk 5 platforms including the UfiSpace S9321-64EO (64×800G OSFP, 51.2 Tbps). This includes Priority-Based Flow Control (PFC), Enhanced Transmission Selection (ETS), DCBX auto-negotiation, Explicit Congestion Notification (ECN), and RDMA-aware queue management — all validated for production RoCEv2 GPU workloads.

! OcNOS 6.6.1 DC -- Complete AI fabric configuration on TH5
!
! Step 1: DSCP-to-CoS mapping for RoCEv2
qos map dscp-cos AI-FABRIC-MAP
  dscp 24 cos 3                   ! RoCEv2 (CS3) -> priority 3
  dscp 46 cos 5                   ! Expedited (EF) -> priority 5
!
! Step 2: PFC on RoCEv2 priority
interface Ethernet1/1
  qos map dscp-cos AI-FABRIC-MAP
  priority-flow-control mode on
  priority-flow-control priority 3 no-drop   ! Lossless for RoCEv2
  priority-flow-control priority 5 no-drop   ! Lossless for control
!
! Step 3: ETS bandwidth guarantees
qos scheduler-group AI-SCHEDULER
  strict-priority 7               ! Highest: network control
  wrr cos 5 weight 10             ! 10%: routing/signaling
  wrr cos 3 weight 70             ! 70%: RoCEv2 (GPU all-reduce)
  wrr cos 0 weight 20             ! 20%: best-effort
!
! Step 4: ECN marking threshold
qos wred AI-WRED
  cos 3 min-threshold 80 max-threshold 95 drop-probability 100
  ecn                             ! Mark ECN instead of drop
!
! Step 5: DCBX (auto-negotiate with GPU servers)
interface Ethernet1/1
  dcbx enable
  dcbx version ieee               ! IEEE 802.1Qaz
!
! Step 6: Apply scheduler to interface
interface Ethernet1/1
  qos scheduler-group AI-SCHEDULER egress
!
! Verification:
show priority-flow-control
show dcbx interface Ethernet1/1
show qos scheduler-group AI-SCHEDULER

Segment Routing Enhancements (SP)

OcNOS 6.6.1 SP expands Segment Routing capabilities with additional Flex-Algo improvements including refined delay advertisement thresholds, improved algorithm convergence during topology changes, and enhanced SR-TE policy path computation. The RSVP Auto-Bypass feature is also introduced in this release — see the RSVP Auto Bypass guide for details.

EVPN Service Expansion

OcNOS 6.6.1 expands EVPN coverage with improvements to EVPN-ETREE service handling, enhanced multi-homed ESI mass withdrawal timing, and improved EVPN IRB (Integrated Routing and Bridging) gateway performance for data center environments requiring simultaneous L2 and L3 forwarding within the same VNI.

• OcNOS 6.6 Release
• OcNOS 7.0 — What’s New
• RSVP Auto Bypass in OcNOS
• OcNOS Feature Matrix
• IP Infusion へお問い合わせ

IP Infusion Product Team