Mark R Lindsey wrote:
"IP Telephony" by Hersent, &al., covers H.323 in some depth. He also covers SIP and MGCP. http://books.google.com/books?id=gC0U-nDGvvsC
Hersent seems to be an H.323 elitist. I get the feeling he really wants to say, "You SIP users are silly children, with your skulls of IETF mush, as if you can re-invent telephony! I spit on your silly extensibility and lack of respect for the great and wise ITU-T fathers."
Despite that, it's quite a useful book.
:) I can understand that perspective, seeing as H.323 was derived explicitly with the goal of being used for telephony signaling and interoperating with telephony systems. SIP comes from an IP/packet design heritage and no intentions of that sort inhere expressly in its conceptual fabric. Having to graft a bunch of old-world stuff onto SIP has definitely created its share of problems and ballooning complexity, although there are other reasons too why it has so many applicable standards documents (lack of strong de facto reference implementation leadership early on, etc.). Nevertheless, the H.323 elitism stance is way out of touch with reality. It's like grumpy Bellheads who insist on building LEC transport cores entirely out of TDM, 'cause this newfangled VoIP stuff is immature and, besides, everyone knows IP networks can't be trusted. Have fun with that. -- Alex Balashov - Principal Evariste Systems Web : http://www.evaristesys.com/ Tel : (+1) (678) 954-0670 Direct : (+1) (678) 954-0671