No, it's not illegal to retry a call to the same gateway (in case of 6xx response).
Nor is it illegal to reject it. :-) My experience in an applied sense with SSTs (SIP Session Timers) is that they are poorly supported, seemingly due to all the state-keeping involved. Many UAs commit to a refresher role, for instance, but don't actually issue the reinvites to refresh. Instead, it is a more commonplace to approach to just use nullary-change reinvites for signalling-level DPD (dead peer detection), without the baggage of SSTs. So for instance, there are a lot of carriers out there whose equipment will just send you a reinvite every 15 minutes to check if you're alive, quite regardless of any SSTs, roles, support for SSTs, etc. -- Alex -- Sent via mobile, please forgive typos and brevity. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
