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 ...

Session Initiation Protocol (SIP) is a control (signaling) protocol developed by the Internet Engineering Task Force (IETF) to manage interactive multimedia IP sessions including IP telephony, ...

Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, modifying and terminating real-time communications sessions between Internet Protocol (IP) devices. SIP ...

You may recall my posted "Blink, Best Damn SIP Client You Never Heard Of!" Unfortunately, at the time I wrote that, only Mac and Linux versions were available. For ...

Session Initiation Protocol is used widely for the setup, teardown and management of VoIP calls. Much of its functionality is related to the setup of calls, as its name implies. Part of this setup ...

For all the technology behind Voice over IP (VoIP), you'd expect that it would work on every network, but this unfortunately isn't the case. Network Address Translation (NAT) is a common practice used ...

A basic guide to tracing complicated call flows on an Avaya Aura system. "If I had an hour to solve a problem, I'd spend 55 minutes thinking about the problem and 5 minutes thinking about solutions." ...

See which SIP trunk providers fit your 2026 voice setup, from fast deployment and transparent pricing to global coverage and PBX support. I’ve looked into just about every business phone system on the ...

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 ...