>>>>> I??aki Baz Castillo <[EMAIL PROTECTED]> wrote: > Hi, the only reference to B2BUA concept I find in RFC 3261 is:
There is draft-marjou-sipping-b2bua. But IMHO it's quite restrictive and reflects somebody's specifics without considering the goal in common. > - Is legal for a B2BUA to change completely the "From" in the second leg?: Yes. Really, B2BUA can do *anything* which doesn't break its functioning. That's why there is no standards for it. But usually B2BUA is used for specific processing which isn't directly allowed for proxy. For example, B2BUA in PortaSIP can connect caller to media server which says post-call words when the main call is finished. Proxy can't do it. > - Should a B2BUA allow unknown headers from leg 1 to leg 2? or should > it create a completely new request from scratch? Initially our B2BUA (based on old Vovida's one) used request modification strategy, i.e. any header which isn't directly deleted or changed by B2BUA was passed through. Later we considered this was invalid decision. Currently it passes only those headers which are directly declared as copied by main logic or by config option. > - Can be problems if B2BUA copies in leg 2 the same "Call-Id" and "From_tag"? Yes, it's roughly incorrect. It can copy call-id, but MUST create new tag, because it creates new dialog. If it were keep dialog unchanged, it would be named "proxy", not "B2BUA". -- Valentin Nechayev PortaOne Inc., Software Engineer mailto:[EMAIL PROTECTED] _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
