<p>So you've been tasked with learning SIP to support and extend your company's VoIP telephony and Unified Communications (UC). But where do you start? An understanding of basic SIP terms is key.What is SIP, and why does it matter?</p><p>What is SIP? The clue is in the name: Session Initiation Protocol. SIP is a peer-to-peer protocol standard developed by the Internet Engineering Task Force (IETF), used for initiatingand also managing and terminatingvoice call sessions over the Internet.</p><p>It's broader than that now, though. SIP can be used for initiating, managing, and terminating other real-time communications, like video and text, as well as voice, and can be used over any IP network, not just the Internet. It's also extensible: SIP can manage other applications, too.</p><p>SIP matters because many organizations have relatively high-bandwidth WAN connections, and an increasing number use SIP to carry voice as well as data traffic over those connections.</p><p><a href="http://www.enterprisenetworkingplanet.com/unified_communications/unified-communications-101-a-glossary-of-sip-terms.html">Keep reading...</a></p>