Abstract: In one embodiment, a method for processing, at an enhanced Session Initiation Protocol (SIP) proxy (e-proxy), (1) a SIP INVITE message to a first user at an IPv4/IPv6 dual-stack (DS) host, connected to an IPv6 network, from a second user at an IPv4 host, connected to an IPv4 network. The e-proxy receives the SIP INVITE message from the IPv4 network. When the e-proxy determines that Dual Stack Transition Mechanism (DSTM) service is required, the e-proxy obtains a temporary IPv4 address for the DS host, finds a suitable tunnel end-point (TEP), and sends a corresponding, but modified, INVITE message to the DS host. The modified INVITE message body includes invocation of DSTM service, the temporary IPv4 address, the TEP's IPv6 address, and the IPv4 host's IPv4 address. The e-proxy sends a BIND message to the TEP to bind the DS host's IPv6 address to the temporary IPv4 address for proper tunneling.

Abstract: In one embodiment, a method for processing, at an enhanced Session Initiation Protocol (SIP) proxy (e-proxy), (1) a SIP INVITE message to a first user at an IPv4/IPv6 dual-stack (DS) host, connected to an IPv6 network, from a second user at an IPv4 host, connected to an IPv4 network. The e-proxy receives the SIP INVITE message from the IPv4 network. When the e-proxy determines that Dual Stack Transition Mechanism (DSTM) service is required, the e-proxy obtains a temporary IPv4 address for the DS host, finds a suitable tunnel end-point (TEP), and sends a corresponding, but modified, INVITE message to the DS host. The modified INVITE message body includes invocation of DSTM service, the temporary IPv4 address, the TEP's IPv6 address, and the IPv4 host's IPv4 address. The e-proxy sends a BIND message to the TEP to bind the DS host's IPv6 address to the temporary IPv4 address for proper tunneling.

Abstract: A method for optimal assignment of customer edge (CE) routers to virtual private network route forwarding (VRF) tables uses a “peer model”, in which the CE routers communicate their routes to a Service Provider's edge routers (PE routers). The routes of a particular VPN are then exchanged among the PE routers that are attached to that VPN. This is accomplished in a manner which ensures that routes from different VPNs remain distinct and separate, even if two VPNs comprise an overlapping address space. The PE routers distribute, to the CE routers in a particular VPN, the routes from other CE routers in that VPN. The CE routers do not peer with each other and, as such, there is no “overlay” visible to a VPN's routing algorithm.

Abstract: A method for optimal assignment of customer edge (CE) routers to virtual private network route forwarding (VRF) tables uses a “peer model”, in which the CE routers communicate their routes to a Service Provider's edge routers (PE routers). The routes of a particular VPN are then exchanged among the PE routers that are attached to that VPN. This is accomplished in a manner which ensures that routes from different VPNs remain distinct and separate, even if two VPNs comprise an overlapping address space. The PE routers distribute, to the CE routers in a particular VPN, the routes from other CE routers in that VPN. The CE routers do not peer with each other and, as such, there is no “overlay” visible to a VPN's routing algorithm.