Lots of questions concerning the B2BUA, The RFC defines a B2BUA, but I am not clear on the role a B2BUA will play in the SIP signalling network, or how it will interact with other logical entities.
draft-rosenberg-impp-presence-01 describes behavior where a SIP network element becomes a B2BUA (for a SUBSCRIBE recieved), OR the element behaves like a proxy, depending on some conditions. Does anyone know of other examples where a network element may become a B2BUA ?? I looked around and could not find a term for the SIP network entity that may have a number of logical behaviors: B2BUA, proxy or redirect. How about Network Server ? What is the advantage of this 'switching' behavior ?? (e.g. between B2BUA, and proxy) Are there examples of a stand alone B2BUA ?? (no switching possible) Are there restrictions on the type of header information a B2BUA is allowed to copy between sessions ?? (when does it start to look like a proxy ...) Line 671 - 676 of bis 05 describe how the same software can behave like one of the logical entities - proxy - redirect server - UAC - UAS on a transaction by transaction basis. Can I include a B2BUA in this list ? Does anyone have good examples of B2BUA applications or call flows ? Is it a 'MUST' to generate other SIP requests in order to gather information on how to respond to a received request ?? Can the B2BUA do something else ... like consult a user.... Why does the RFC state in the B2BUA definition that it keeps state "unlike" a proxy ?? It seems that a proxy may also keep state, of a complete call if it likes. -- Francois Lessing Trillium Digital Systems, an Intel Company Los Angeles, USA Tel: +1 310 481 5937 Fax: +1 310 481 5558 _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
