SIP rollouts hit variety of snags

摘要

Commercial VoIP service rollouts are taking longer than anticipated as early adopters of Session Initiation Protocol experience unexpected interoperability problems with the increasingly important communications mechanism. SIP is the emerging standard for setting up telephone calls, multimedia conferencing, instant messaging and other types of real-time communications on the Internet. An array of network gear including IP phones, IP PBXs, servers, media gateways and softswitches support SIP. The interoperability problems stem from vendors taking different approaches to SIP features such as device registration, user authentication and firewall traversal. The problems range from failed user logons that cause systems to crash to annoyances such as difficulty transferring calls. Of particular concern to experts is that some vendors have not followed the SIP guidelines for fail-over when a server goes down. Companies that buy SIP servers without the correct failover mechanisms are more likely to experience service outages, experts say.