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, ...

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 ...

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 ...

In this chapter, we start putting into practice some of the SIP concepts learned so far. We will show some very simple programming examples that illustrate how SIP works. As was stated in previous ...

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 ...

Update: We're in the last throes of winter break 2019, which means most Ars' home office phones can stay dormant for a few more days. As such, we've been resurfacing a few classics from the ...