Content for TR 23.981 Word version: 17.0.0
5 Architectural concept p. 9
5.1 General p. 9
5.2 UE access to IM CN subsystem p. 10
5.2.1 Obtaining IP address and P-CSCF discovery p. 10
5.2.2 Scenarios p. 11
5.2.2.1 IMS dual Stack UE accessing an IM CN subsystem p. 11
5.2.2.2 IPv4 UE and IPv4 based IM CN subsystem Implementation p. 11
5.2.2.3 IPv4 UE and IPv6 based IM CN subsystem p. 12
5.2.3 IP Versions in UE and P-CSCF p. 12
5.2.4 IP Versions in SGSN and GGSN p. 12
5.3 Interworking scenarios p. 12
5.3.1 Interworking architecture and NATs p. 12
5.3.1.1 Interworking architecture p. 12
5.3.1.2 NATs p. 13
5.3.2 Overview p. 13
5.3.3 Non-roaming access to IMS scenarios p. 14
5.3.3.1 Non-roaming - IPv4 IM CN subsystem p. 14
5.3.3.2 Non-roaming dual stack IM CN subsystem p. 14
5.3.3.3 Non-roaming IPv6 IM CN subsystem p. 15
5.3.4 GPRS access scenarios p. 15
5.3.4.1 Non-roaming scenario, dual stack home network p. 15
5.3.4.2 Roaming - IPv4 visited network, dual stack home network p. 15
5.3.4.3 Roaming - IPv4 visited network, IPv6 IMS home network p. 16
5.3.4.4 Roaming - dual stack visited network, IPv4 GGSN and Dual stack IMS p. 17
5.3.4.5 Roaming - dual stack visited network, IPv6 home network p. 17
5.3.5 Interconnection and end-to-end scenarios p. 18
5.3.5.1 Overall Scenario p. 18
5.3.5.2 NAT/ALG between IMS entities within one operator's IMS network p. 19
5.3.6 Summary of issues arising from the scenarios p. 20
5.3.7 IP version interworking for services p. 20
5.4 Migration scenarios p. 22
5.4.1 IPv4 UE and IPv6 IM CN subsystem p. 22
5.4.2 A partially migrated IPv4 to IPv6 IM CN subsystem p. 22
5.4.3 Migration aspects for services p. 22
5.4.3.1 Application Servers p. 22
5.4.3.2 Migration support in dual stack IM CN subsystem p. 22
5.4.3.3 Access to network services p. 22
5.4.4 Example migration paths p. 23
6 Conclusions and recommendations p. 23
A Additional Information p. 24
A.1 GPRS deployment scenarios p. 24
A.1.1 IMS roaming access - IPv4 visited network, IPv4 home network p. 25
A.1.2 IMS roaming access - IPv4 visited network, IPv6 home network p. 25
A.1.3 IMS roaming access - IPv6 visited network, IPv4 home network p. 26
A.1.4 IMS roaming access - IPv4 visited network, dual stack home network p. 26
A.2 End to End scenarios p. 27
A.2.1 Non-roaming - IPv4 IM CN subsystem with IPv6 IM CN subsystem p. 27
A.2.2 Non-roaming - IPv4 IM CN subsystem with IPv4 IM CN subsystem p. 27
A.2.3 Non-roaming IPv4 IM CN subsystem with dual stack IM CN subsystem p. 28
A.2.4 Non-roaming dual stack IM CN subsystem with dual stack IM CN subsystem p. 29
A.2.5 Non-roaming IPv6 IM CN subsystem with dual stack IM CN subsystem p. 29
$ Change history p. 31
