Ebook: The IP Multimedia Subsystem (IMS): Session Control and Other Network Operations

When I received the book I kind a felt that well another waste of money due to size and amount of content I had been delivered. "Hey at least read what you have in your hand!" I said to myself.

Here comes the results:

+ This book has certain errors: Figure 1.3 (I- talking to AS instead of S-, S- is not talking to HSS)/1.6(S- is not talking to AS)/1.7 (S- is not talking to MGCF)/1.8 are all misleading in the name of 3gpp specifications. By chance we got Figure 1.9 that is cleaning all these errors done in previous pages.

+ SLF explanation has this phrase: "When P-CSCF needs to route a request for a subscriber session to the appropriate S-CSCF, the P-CSCF would access this function to determine which S-CSCF has been assigned to the subscriber" this means SLF is used instead of P-CSCF internal caching role.

+ Application Server (AS) has this phrase: "AS can communciate with other AS, for example; AS can act as a redirect server generating requests and sending responses to other SIP entities within IMS" I assume we are talking about SCIM here somehow but SCIM has not given explicitly and correctly in my understanding.

+ MGCF has this phrase: "SS7 message sent to MGCF mapped to SIP Request and forwarded to P-CSCF" without stating whether orig/half call services.

+ SIGTRAN variously explained over the book couple of times unnecessarly.

I encouraged my self to keep reading after all those chapters. If you are looking for a book that explains IMS and technical details in the light of 3gpp I strongly advice not to buy this book but take a look at other available ones (ex;Camarillo's book) instead.

Mr. Russell, I don't think that I am gonna buy your next book whose title given here (SIP).