keccles wrote: > Robert Joly <rjoly <at> nortel.com> writes: > >>> http://track.sipfoundry.org/browse/XECS-1594 >>> >>> Hi, >>> >>> I am looking into using in-dialog OPTIONs to implement a >>> keep-alive mechanism for the MOH and park server. >>> > <snip> > >> As a point of reference, the NAT Traversal feature also relies on >> sending OPTIONS to keep NAT bindings alive and that is not causing any >> trouble with the phones that I tested with: LG, Polycom and Counterpath. >> > Is there any reason NOT to use exclusively OPTIONS for this keep alive? A > fix > was developed that uses OPTIONS for MOH but uses re-INVITEs for calls in park > orbits. Using only OPTIONS would simplify this fix and simplify things for > sipXbridge. From Robert's NAT comment it semms unlikely to complicate or > break > other parkers (ie phones). > > Any objections to OPTIONS only? > > -Kathy >
I agree that using only OPTIONs will simplify the code and the call processing, but I think re-INVITEs are a much more reliable way to do keep-alives. When using in-dialog OPTIONs we are limited to parsing only a 404, 408, or 481 response, for marking dialogs as terminated. This was done to support phones that don't support OPTIONs. So, not only are we relying on the far-end phones to send back the correct error response, but we are also assuming that they see a difference between in-dialog OPTIONs and out-of-dialog OPTIONs. Arjun _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev
