Tag Archives: Session Description Protocol

It Takes More Than SIP to Get the Job Done

As a Minnesotan on the cusp of another long and cold winter, March feels like a lifetime away. While I have the holidays to lift my spirits here in the month of December, January and February are nothing more than snow, ice, and sub-freezing temperatures.   It gets so bad that there will come a time […]

A Wireshark View of Real-Time Protocol (RTP)

Despite the fact that we’ve entered the holiday season, the weeks between Thanksgiving and New Years are proving to be some of the busiest of the year. Last week I was in Tampa and this week I travel to Salt Lake City and Phoenix.   It doesn’t stop there, though. Next Monday, I fly to Detroit […]

Dissecting a SIP Conference Call

Every few months, I teach a two and a half day class on all things SIP. I cover every request and response messages, most of the headers, and the students use Wireshark with a SIP softphone to do in-depth call flow analysis. These flows include basic and sophisticated telephone calls, presence, and instant message. I […]

Come Together: A Collection of Articles Designed to Make you a SIP Rock Star

I have been working on this blog for a little more than a year and in that time I’ve written articles about a wide range of topics related to unified communications. From the beginning, it has been my goal to create articles on subjects that are current, interesting, and relevant to those of us who […]

An Introduction to WebRTC Signaling

There is something you need to know about me. When I get excited about something, I tend to get really excited. Case in point is WebRTC. I’ve seen a lot of amazing ideas, inventions, and products in the field of communications, but the notion of turning a web browser into a full featured multimedia communications […]

The Anatomy of an INVITE Request

As a high school student, I loved biology. I loved learning about the natural world and how our bodies function. The spleen was my friend — not to mention the pancreas, liver, and lungs. Unlike many of my classmates, I didn’t mind dissecting frogs and the obligatory fetal pig. Okay, I wasn’t overly fond of […]

SIP Media Management: Early Offer vs. Late Offer

I hate being late. Just ask my wife. She has grown used to the fact that I like being in our seats at least 20 minutes prior to the start of a movie, but she never fails to point out that we are the only ones in the theater at that time.  Thankfully, she has […]

Converge2014: Building a Secure SIP Network

For the most part, I love my job.  I love sifting through Wireshark traces trying to find needles in SIP haystacks.  I get excited learning about new IP communications products.  My heart practically skips a beat when I read about another SIP service climbing out of its physical shell and going virtual. However, the best […]

How to Debug SIP

When I was younger I had two careers in mind – a college professor or a radio disc jockey.   For better or worse, I ended up being a software developer at a telecommunications company.  I can’t complain too much, though.  I worked on a number of really cool projects.  I’ve traveled all around the world […]

Understanding Session Description Protocol (SDP)

It’s impossible to truly understand SIP without understanding its cousin, Session Description Protocol (SDP).  While SIP deals with establishing, modifying, and tearing down sessions, SDP is solely concerned with the media within those sessions.  That SIP would relegate media to another protocol is not accidental.  The creators of SIP set out to make it media […]