In our last VoIP installment, we looked at the main reasons why SIP has become a widely adopted protocol, but we left details of the protocol’s inner workings fairly vague. This article will drill ...

The iptel.org 180+ page SIP tutorial is outstanding. Another overview that is a bit more market-oriented and nearly as long. White paper on the SIP value proposition over telephony, SIP and the new ...

Even many IT professionals haven't heard of the Session Initiation Protocol (SIP), so it's almost certain your users haven't. However, unless you're using an entirely proprietary Voice-over-IP (VoIP) ...

As SIP continues to seep into the mainstream, more attention is being paid to security issues, especially in public IP networks/the Internet. At VoiceCon Orlando in March, we're bringing back Cullen ...

The main challenge: Even if an enterprise wants to interconnect different IPT islands, there is no real incentive for two different vendors to interoperate. VoIP/IPT systems have proliferated to the ...

Even many IT professionals haven't heard of the Session Initiation Protocol (SIP), so it's almost certain your users haven't. However, unless you're using an entirely proprietary Voice-over-IP (VoIP) ...

In Part 1 of our SIP primer, I covered the SIP foundation layers starting from the message structure and ending with the SIP transactions. We saw how phone registrations and proxies could work using ...

What's VoIP's Big Security Problem? SIP Session Initiation Protocol (SIP) is a must for voice over IP (VoIP) communication. But by itself, SIP is insecure and easily hacked. Here's what you need to ...