dpoints and a SIP-based architecture upon which applications can be built. E2E Network Architecture and Mobility Management that can address interoperability challenges, IMS will be more meaningful and customers will truly enjoy benefits of convergence in the wireless domain. 11.9.1.2.2.2 IMS in Packet Cable Domain PacketCable is a CableLabs specification effort designed to support the convergence of voice, video, and data. It also aims to support mobility services and interoperability with cellular and wireless networks [20]. PacketCable is based on IMS as defined in the Release 6 of 3GPP. PacketCable reuses many of the basic functional entities and reference points defined in the IMS. The primary motivation behind this design objective is to align with a set of standards that are widely supported by vendor products, and therefore, minimize the product development effort required to deploy PacketCable networks. While many of the functional entities and reference points defined in the IMS have broad applicability in other industries, Release 6 of the IMS is a wireless-centric architecture; designed to meet the business and operational needs of the wireless industry. Therefore it does not meet all of the needs of the cable industry. PacketCable enhances the IMS to support the unique technology requirements of the cable industry, and also addresses cable operator business and operating requirements. The extensions include use of additional or alternate functional components compared with the IMS architecture, as well as enhancements to capabilities provided by the IMS functional components. Some of the key PacketCable enhancements to the IMS include: Support for QoS for IMS-based applications on DOCSIS9 access networks, leveraging the PacketCable Multimedia architecture. Support for signaling and media traversal of Network Address Translation and Firewall devices, based on IETF mechanisms. Support for the ability to uniquely identify and communicate with a specific UE when multiple UEs are registered under the same