Liquid Telecom Liquid Telecom Juniper Networks This document describes a new BGP extension for signalling the mapping between Segment Identifiers (SID's), as used by a SRm6 Compressed Routing Header (CRH) and the IPv6 Addresses they represent. The extension defines both a new optional BGP attribute to signal the Maximum SID Value (MSV) and a new Sub-Address Family (SAFI) of the IPv6 Address family.