21 of 23 people found the following review helpful
Not bad, but not the best,
By A Customer
This review is from: Sip: Understanding the Session Initiation Protocol (Artech House Telecommunications Library) (Hardcover)
I found the book useful as a backup reference to the spec, but not the best explanation I have seen. It was at times slightly confusing, and found that I was constantly referring back to the SIP overview in D. Collins "Carrier Grade Voice over IP" (which is very well written). From an education perspective, it was a little like a dictionary for SIP that explained concepts such as what a given header was for, but gave little info on how it is used, or what the industry is doing.
There were some call flows, but they were sparse with a few mistakes. Further, they were either very base, or very comprehensive, and did not cover many of the questions I had.
In summary, if you are looking for a readable reference to help with the not so reader friendly RFC, this is pretty good. For learning how SIP is being imlemented beyond basic call handling, keep looking.
As an option, also look at the book by Collins noted above. It is a good overview reference, and tries to address where the industry is moving from an implementation perspective