TWAMP probes in segment routing

We have added support in Two-Way Active Measurement Protocol (TWAMP) for segment routing (SR) as defined in RFC 8402, which broadly specifies the SR architecture. We support two types of SR for TWAMP probes:

• SR-MPLS: Uses a list of labels, each representing a segment end node.
• SRv6: Uses a type 4 IPv6 routing header introduced in RFC 8754, with each segment end node represented as an IPv6 address or IPv6 segment identifier (SID).

You can specify the list of SR-MPLS or SRv6 segments for a TWAMP probe to reach the reflector. In addition, you can specify the same information for the return path from the reflector to the client. This return path information is embedded in the probe itself by using the extensions proposed in Simple TWAMP (STAMP) Extensions for Segment Routing Networks, draft-ietf-ippm-stamp-srpm, namely the return path TLV and its return segment list sub-TLVs, as appropriate depending on the segment routing type. The TWAMP probes are timestamped in either the Routing Engine or the Packet Forwarding Engine.

To configure this feature, include the source-routing statement at the [edit services monitoring twamp client control-connection name test-session session-name] hierarchy level.