> AFAIK RFC-4028 defines that proxy can reject with 422 > to define a *higher minimum* for session timer but > wondering why there is no provision to define a > *lower maximum*. Does it never form a valid use-case ?
It is a valid use case. The two devices are not interoperable within the specific deployment. The caller or prior proxy requires Min-SE to be higher than the maximum Session-Expires of another proxy. If the proxy refuses to accommodate the larger Session-Expires, it can reject the INVITE with 403 (or another response) or allow the call to be setup and potentially have issues caused by the proxy expiring the dialog. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
