________________________________________ From: [email protected] [[email protected]] On Behalf Of Olle E. Johansson [[email protected]]
Here at SIPit we had a test involving B2BUA's in spirals and loops and other dangerous situations. Robert Sparks and I ended up with a discussion about how B2BUA's should handle Max-Forwards. http://tools.ietf.org/html/draft-marjou-sipping-b2bua-01 The BCP draft clearly says that B2BUA's should RESET the Max-Forwards header. "Max-Forwards R Reset Max-Forwards when creating requests [3]" In appendix A. Robert meant that if we do NOT decrement max-forwards with one as we set up the new call, we will cause endless loops. I'm stuck in between. In some situations, like a PBX, the new call is really a new call. When using a B2Bua as an SBC, we do forward calls. _______________________________________________ Surely the text in draft-marjou-sipping-b2bua is a bug, and Max-Forwards of the outgoing request should be 1 less than Max-Forwards of the incoming request. I'm sure there are some situations where a B2BUA originates a dialog in a way that is not logically the extension of an incoming dialog, and in those cases, it can choose Max-Forwards by another method. But those are not the situations that draft-marjou-sipping-b2bua is intended to cover. Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
