Force, August 2003. 53. Wiljakka, J. Analysis on IPv6 Transition in Third Generation Partnership Project (3GPP) Networks. RFC 4215, Internet Engineering Task Force, October 2005. 54. 3GPP, Interworking aspects and migration scenarios for IPv4-based IP Multimedia Subsystem (IMS) imple- mentations. TR 23.981, 3rd Generation Partnership Project (3GPP), December 2009. 55. 3GPP. IPv6 migration guidelines. TR 23.975, 3rd Generation Partnership Project (3GPP), June 2011. 56. Arkko, J., Eggert, L., and Townsley, M. Scalable Operation of Address Translators with Per-Interface Bindings. RFC 6619, Internet Engineering Task Force, June 2012. 57. GSMA. IPv6 EMC Task Force; Roaming and Interoperability Impacts of IPv6 Transition Whitepaper. White Paper 1.2, GSM Association (GSMA), March 2011. 58. GSMA. GSMA PRD IR.33 GPRS Roaming Guidelines. PRD IR.33 6.0, GSM Association (GSMA), May 2011. 59. GSMA. Inter-Service Provider IP Backbone Guidelines. PRD IR.34 5.0, GSM Association (GSMA), December 2010. 60. GSMA. GSMA PRD IR.40 'Guidelines for IP Addressing and AS Numbering for GRX/IPX Network Infras- tructure and User Terminals'. PRD IR.40 5.0, GSM Association (GSMA), December 2010. 61. GSMA. GSMA PRD IR.40 DNS/ENUM Guidelines for Service Providers and GRX/IPX Providers. PRD IR.40 7.0, GSM Association (GSMA), May 2012. 62. GSMA. GSMA PRD IR.88 LTE Roaming Guidelines. PRD IR.88 6.0, GSM Association (GSMA), August 2011. Future of IPv6 in 3GPP Networks The evolution of Internet Protocol version 6 (IPv6) in the 3rd Generation Partnership Project (3GPP) networks is nowhere near complete. In fact, the commercial deployments of the features we have described in the first five chapters have hardly even begun yet. The future is likely to bring fine tuning of the basic IPv6 features, as the industry gains more operational experience from the actual deployments and as academia discovers improvement needs via research. In 3GPP networks the Stateful Dynamic Host Configura- tion Protocol version 6 (DHCPv6) (see Section 3.5.2) may gain traction,