Porting the session initiation protocol to IPv6

A modified Java-based SIP (session initiation protocol) implementation offers one approach to developing multimedia services that run on both IPv4 and IPv6 networks. This article describes our experiences in porting SIP to lPv6. To deploy a service in which IPv6 nodes communicate with IPv4 nodes, we selected an IPv4-IPv6 transition mechanism that combines an application-level gateway (ALG) with network address translationprotocol translation (NAT-PT) for application traffic. Our solution required us to make several modifications to the original JSIP library.