Ars Technica

VoIP in-depth: An introduction to the SIP protocol, Part 2

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 ...
No Jitter

Fixing a SIP Security Hole

RFC 4474 implements Public Key Infrastructure (PKI). This provides an authenticated identity for the originator of a VoIP call. There is a security hole in the SIP protocol. According to John Nix, VP, ...
Linux Journal

A Linux-Based Implementation of Mobility Using SIP

The session initiation protocol (SIP) is one of the most popular signaling protocols used in applications that require a session setup and parameter negotiation before actual communication, as well as ...
Network World

Telephony Protocols

This excerpt is from CCIE Voice Exam Quick Reference Sheets (Digital Short Cut), by Mark Lewis and published by Cisco Press. ISBN-10: 1-58705-333-0 Read Mark Lewis’ blog for Cisco Subnet here. More ...
Ars Technica

VoIP in-depth: An introduction to the SIP protocol, Part 1

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 ...