If there is no danger about it, I would rather that the default behaviour was to pass on the headers.
If we leave it as it is: Any header used for debugging (like Reason) might not work. Any proprietary/custom headers in CANCEL are doomed. But it's probably too late in the day to fix this. What about a workaround? You can't even encode your customised junk into the CANCEL's Via header because each CANCEL leaving a stateful proxy will only (normally) have one Via. Are there any workarounds? Hacking the To or From or Contact? Regards, Attila -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Iñaki Baz Castillo Sent: 09 February 2009 13:59 Cc: [email protected] Subject: Re: [Sip-implementors] "Reason-Header" inCANCELthroughvariousproxies 2009/2/9 Attila Sipos <[email protected]>: > So if any new header wants to be used in a CANCEL, then all proxies > have to be software-updated. New headers for CANCEL won't be > guaranteed to work unless every proxy in the path is updated. > > That's an awkward default. > > Ok, so I understand the rules, but what is the reason for this? > What are the problems/dangers of copying CANCEL headers across? I thinks this is due to the original design of CANCEL. CANCEL is supposed to cancel a call, no more. And it's designed as hop-by-hop so there was no requeriment of bypass custom headers. I don't think there is problem/danger about it, but more a matter of original design and specification. BTW, are there other headers in CANCEL that could be bypassed in order to get some feature (as "Reason" header)? -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
