China Mobile China Mobile Centec Networks Centec Networks Centec Networks This document specifies SRv6 (Segment Routing over IPv6) extensions for multicast delivery of RDMA (Remote Direct Memory Access) Reliable Connection (RC) traffic. It defines a new SRv6 endpoint behavior, End.MT, that performs per-receiver RDMA Base Transport Header (BTH) modifications at edge nodes of the multicast tree. It also specifies procedures for hop-by-hop aggregation of RDMA ACK, NACK, and CNP response messages along the reverse path. Together, these extensions allow RDMA RC endpoints to communicate using standard point-to-point Queue Pair (QP) semantics while the network distributes data packets over an IP multicast tree. Target deployment scenarios include multi-replica distributed storage writes, HPC collective communications, AI training parameter distribution, and large-scale inference KV cache distribution.