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 ...

H.323, the ITU's umbrella standard for audio, video and data-sharing over packet (IP) networks, is already widely deployed and has significant market share. SIP, the IETF's multimedia signaling ...

Last time I gave a high level overview of SIP and also took a look at SIP network element types. This time, I’ll be looking at SIP message and method types, and describing how SIP network elements ...

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 ...