Hi all, is there a way to make freeswitch send a 423 (Interval Too Brief) during a SIP REGISTER request? I want to prevent clients to (re)register with a low expire-time and thus spam our network. The "sip-force-expires"-variable would work but don't seem to be SIP-compliant to me.

From RFC 3261:

10.3 Processing REGISTER Requests When receiving a REGISTER request, a registrar follows these steps: (...) 7. The registrar now processes each contact address in the Contact header field in turn. For each address, it determines the expiration interval as follows: - If the field value has an "expires" parameter, that value MUST be taken as the requested expiration. - If there is no such parameter, but the request has an Expires header field, that value MUST be taken as the requested expiration. - If there is neither, a locally-configured default value MUST be taken as the requested expiration. The registrar MAY choose an expiration less than the requested expiration interval. If and only if the requested expiration interval is greater than zero AND smaller than one hour AND less than a registrar-configured minimum, the registrar MAY reject the registration with a response of 423 (Interval Too Brief). This response MUST contain a Min-Expires header field that states the minimum expiration interval the registrar is willing to honor. It then skips the remaining steps. Thanks in Advance, Adam