Juha Heinanen wrote: > Maxim Sobolev writes: > > > All this has nothing to do with the SIP, really. It just illustrates the > > point that SIP proxy is bad choice for real-time VoIP accounting. > > i didn't notice that someone in this discussion would have suggested to > use sip proxy for accounting. accounting in the examples was done pstn. > > i do agree with dan here and do consider it sip protocol's fault if sip > proxy working according to rfc3261 can ignore user's request to cancel > a call.
No, it's not ignoring request. The proxy is dialog-ignorant component, it should not add any new state to the dialog between endpoints. If network delays generation of the final negative reply for whatever reason, so that should the proxy do. As I said technically this case is no different from UA placing a call to another UA directly. If you want to isolate ingress and egress dialog state and bill user only for what he has actually sees use b2bua. Then you will be able to end ingress call with 487 immediately upon receiving CANCEL and don't bill user for anything that happens on the other side after that, letting egress calls to complete independently and not affect what user sees in her bill. It's just a matter of trust and control - by using a proxy you let user's device to set up direct dialog with potentially hostile party that can exploit protocol weakness for its benefit. All those "abuse" examples are resulting from that. SIP protocol is only responsible for making sure the dialog state is consistent end-to-end, it doesn't and shouldn't care about whether or not parties on both ends are fair to each other. Regards, -- Maksym Sobolyev Sippy Software, Inc. Internet Telephony (VoIP) Experts T/F: +1-646-651-1110 Web: http://www.sippysoft.com _______________________________________________ Devel mailing list Devel@lists.openser.org http://lists.openser.org/cgi-bin/mailman/listinfo/devel