11.4 MC gateway UE routing capabilities

23.2803GPPCommon functional architecture to support mission critical servicesRelease 18Stage 2TS

11.4.1 General

The use of the MC gateway UE requires the support of an IP network behind the MC gateway UE, that a range of IP addresses are reachable over a single MC gateway UE. That enables the forwarding of signalling information and media plane between no-3GPP devices and MC server by the MC gateway UE.

11.4.2 MC client IP address association

The use of a unique IP address by the MC clients shall be ensured for the period of association of the MC clients via the MC gateway UE with the IMS/SIP core and the MC server. Each MC gateway UE requires a unique IP address range for their MC client association which is known by the MC service environment and a correlation between the MC client’s IP address and the MC gateway UE’s IP address exists.

Figure 11.4.2-1: MC client IP address relationship

Framed routing in accordance with IETF RFC 2865 [32], IETF RFC 3162 [33], 3GPP TS 23.501 [34] shall be used to enable the support of an IP network behind the MC gateway UE, such that a range of IP addresses is reachable over a single 3GPP transport session. It allows the routing of packets to IP addresses that do not belong to the PDN/PDU session of the MC gateway UE.

NOTE: The MC gateway UE can provide necessary IP address allocation to MC clients, e.g., as a DHCP relay agent in accordance with IETF RFC 1541 [35] and IETF RFC 8415 [36], or as a requesting router in accordance with IETF RFC 8415 [36] and 3GPP TS 23.401 [17] when using IPv6 prefix delegation.