IPv4 and IPv6 Migration in IMS Environment

The IP Multimedia Subsystem (IMS) framework was envisioned to be operating on an IPv6 network. However, when the fixed network started to use IMS framework in the Next Generation Network (NGN) architecture, the issue of IPv4 and IPv6 interworking becomes more pronounced due to the widespread usage of the IPv4 network. The overall objective of the solution proposed in this article is to minimize the invocation of Network Address and Port Translation Protocol Translation (NAPT-PT) or Network Address and Port Translation (NAPT) inside the provider’s network. The solution, outlined by the processing rules contained in this article, will limit the NAPT-PT operation at most once inside the provider’s network under all the situations for the media path. This solution will also introduce the minimum required NAPT operations.