[SIPForum-discussion] SIP Registrar (request processing order/423 intervall too brief)

[Martin Weiglhofer]

Dear all,

I have two questions regarding the SIP-Registrar.

(1) Is the ordering of the steps for processing a REGISTER-Request given
in Section 10.3 of RFC3261 mandatory? Or may an implementation execute
the steps in an arbitrary (of course reasonable) order. For example, is
an implementation which rejects an invalid request (because of invalid
contact header fields, step 6) before authorizing the user (step 5)
conform to the specification?

(2) The RFC3261 says, "the registrar MAY choose an expiration less than
the requested expiration interval" and under some circumstances it "MAY
reject the registration with a response of 423 (Interval Too Brief)". Is
the registrar allowed to extend the expiration interval (e.g. the
requested expiration value is 300, but the registrar uses 600)?

Thanks in advance.

Best regards
Martin