SIP: Creating Next-Generation Telecom Applications 18
An anonymous reader writes "In this article, you'll discover how the Session Initiation Protocol (SIP) operates and, building on that knowledge, you will learn how to use the Java SIP Servlet API to build new applications that can run on telecommunications networks. The SIP tour concludes with code examples that demonstrate SIP application development in action."
When all you have is a hammer.... (Score:2, Insightful)
While the HTTP request/response model has served the IETF well enough for many things, perhaps they should consider more protocol models than the single hammer they seem to have equipped their toolbox with.
Re:When all you have is a hammer.... (Score:3, Interesting)
Second, SIP was developed when HTTP request/response seemed like the new way of doing a lot of stuff. It has disadvantages (verbose, textual, lot of cruft you don't need) and advantages (already specified, clear way of extending it, MIME support)
Third, SIP and other protocols used/specified by the telecom industry tend to have layer upon layer
Re:When all you have is a hammer.... (Score:1)
Huh? Last time I checked, the major alternatives were SIP and H.323. H.323, not SIP, is the overspecified, layered monster from the telecom industry. (Although I'm sure SIP sucks, too.)
Huh? (Score:1)
Also notice that SOAP uses HTTP for RPC. HTTP is hardly bulk anymore.
Re:Huh? (Score:1)
SIP devices start ringing before their bearer (RTP) is connected (i.e. 180 Ringing is before RTP stream gets set up). In contrast, a black phone (regular telephone) won't start ringing (alerting) until the bearer is connected. This has usability issues, because people are used to the way that regular telephones operate. If the bearer fails on a SIP phone, the phone call can still connect (i.e. the signalling worked), which can confuse both users.
Yes... (Score:4, Interesting)
Another great contribution to providing free public documentation by IBM. Kudoes to them.
Meanwhile, there's that oncoming train [techweb.com] about states requiring VoIP providers to become fully bureaucratically functional telephone providers....
A good dose of well-meaning out-dated regulation ought to slow down the adoption rate of good new technology.
How SIP operates...? (Score:1, Insightful)
For instance, it does not get into SIP message forking, spiralling, and time outs, nor does it explain how the ACK (the only request which does not get a response) is sometimes considered part of the INVITE transaction, and sometimes it is not, nor how authentication works, or message encryption.
No mention of the use and differences between CANCEL and BYE.
There appears to be only a brief
how does SIP compare to Jabber? (Score:2)
Anyone has opinions on that?
Re:how does SIP compare to Jabber? (Score:1, Interesting)
Re:how does SIP compare to Jabber? (Score:1, Informative)
Re:how does SIP compare to Jabber? (Score:1, Informative)
It's common misunderstanding. SIP is only for session initiation. For content exchange You have SDP protocol for example, which very often comes together with SIP.
INFORMATIVE? It's DISinformative! (Score:2)
Where did you get this crazy misunderstanding? Jabber uses XMMP, which is lightweight protocol. Well, jabber uses H.323 - but only for voice over IP extensions/applications, not for regular sessionmanagement.
Who is the idiot that modded up the parent as "informative"? Check the "information" before you rate it!