Recommendation ITU-T Q.3630 v.1 specifies requirements for the Inter-IMS Network to Network Interface (NNI)". The version number, v.1, indicates that this is version one of Recommendation ITU-T Q.3630, and that it relates to Release 10 of the relevant 3GPP/ETSI standard. This Recommendation endorses the ETSI TS 129 165 V10.21.0 (2016-01) Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); LTE; Inter-IMS Network to Network Interface (NNI) (3GPP TS 29.165 version 10.21.0 Release 10).