2008/8/16 Paul Kyzivat <[EMAIL PROTECTED]>: > Iñaki, > > AFAIK there is little in the way of standards for B2BUAs. > > The problem with standardizing B2BUAs is that they can be used for many > different purposes. There is virtually nothing that you can say *in general* > that will apply to all B2BUAs beyond what 3261 says - that they must satisfy > all the rules for UAC and UAS. > > To provide any meaningful standards/guidance, it is necessary to narrow the > scope. There are some instances of this: > > - conference controllers: there are standards for a conference focus, > which is one sort of B2BUA. > > - presence server: this is *loosely* a B2BUA connecting presence > publishers and presence subscribers. > > - exploders: there are some standards for these, to do 1:many > message sending. > > - mobility: some of the mobility stuff is really describing B2BUA > behavior. > > What has not been specified much is SBC behavior. I guess that is really > what you are asking about. This isn't very much defined, and I suspect many > like it that way. SBC's are deployed for the purposes of protecting, hiding, > and fixing things. They tend to be highly configurable as to what they > do/don't propagate, etc. based on the whims of the operator deploying them. > It seems that often an operator will *intentionally* want to break certain > kinds of usage, and so may do things that seem wrong. These things are often > deployed in environments where only certain kinds of usage are expected, and > so breaking other sorts of usage is not considered a problem. For instance, > rewriting various URIs can be done many ways if your only goal is to support > signaling based on "phone numbers". > > But the net effect is that lots of "novel" usage that would work fine in a > system where there are only proxies between the UAC and UAS will *not* work > in networks containing SBCs. In each case it might eventually be possible to > *make* something new work by tweaking the SBCs to support it. But it thus > puts the SPs deploying those SBCs in the position of being gatekeepers for > what technology is usable.
Thanks a lot for so good explanation. -- Iñaki Baz Castillo <[EMAIL PROTECTED]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
