A single reference for the specifications, IETF drafts and open-source releases that define SRv6 in AI networks. Status as of 20 October 2026. Drafts are individual submissions unless noted; an IETF draft is a work in progress and carries no standards status until it is published as an RFC.
Title: SRv6 for Deterministic Path Placement in AI Backends (Informational).
Authors (-05): Cisco, OpenAI, Microsoft, Oracle, IBM, NVIDIA and Arrcus.
History: started as draft-filsfils-spring-srv6-ai-backend-00 (April 2025); -00 to -02 in July–August 2025, -03 in March 2026, -04 in June 2026, which added the statically provisioned fabric and the MRC deployment section, and -05 in September 2026.
Content: no new protocol. It specifies how a NIC uses H.Encaps.Red with uN (or uA) uSIDs to pin each packet's path, why the fabric can be static, how to probe deterministically, how to extend across data centers, and its security considerations.
Static SRv6 via CONFIG_DB (SRV6_MY_LOCATORS, SRV6_MY_SIDS) with uN and uDT46; announced as SRv6 support for source-routed AI backends
SONiC 202511
Ships FRR 10.4.1 (static uA available in FRR); CONFIG_DB still uN and uDT46
SONiC 202605
Ships FRR 10.5.4; CONFIG_DB still uN and uDT46
SONiC master
uA in CONFIG_DB (merged August 2026), FRR 10.7.1, warm-boot for static SIDs
SAI
saisrv6.h defines uN, uA, uDT4/6/46 and uDX4/6 endpoint behaviors and reduced-encapsulation SID lists
FRR 10.4 / 10.5
Static uA (10.4); multiple uSID locators, F4816 and static uSID in the global table (10.5)
The 2025 SONiC AI-backend effort merged 122 pull requests across SAI, SONiC and FRR. By mid-2026 the overall SRv6 work totaled more than 460 pull requests, led by Cisco with Microsoft, Alibaba, Broadcom and NVIDIA. Details: SONiC, SONiC & SAI, FRRouting.
Is there an IETF standard for SRv6 in AI data centers?¶
The data-plane standards already exist: RFC 8986 (behaviors) and RFC 9800 (uSID). The AI-specific usage is described in draft-filsfils-srv6ops-srv6-ai-backend, an Informational individual draft at revision -05 (September 2026) whose authors requested working-group adoption at IETF 126. It defines no new protocol.
No. MRC (Multipath Reliable Connection) is an Open Compute Project specification, OCP MRC 1.0, released in May 2026. It uses SRv6 as one of its forwarding modes.