Request timeouts are 408, NOT 487 status codes

[hkaplan@…]

Section 6.3.3 says:

If a request has timed out (instead of being explicitly rejected), it
SHOULD be treated as if a 487 "Request Terminated" error response
code was received.

Using 487 for this is also mentioned in section 5.1.2.

Why? That is not what SIP does. A request timeout is a 408. A 487 is used for an explicit INVITE early termination (i.e., through a CANCEL), although rfc3261 also says to use it if an INVITE's Expire header value's time fires (section 13.3.1 of 3261), but that's not a "request timeout" (and really 3261 contradicts itself for using 487 for Expires too, in section 21.5.5).

Change this to 408, in sections 5.1.2 and 6.3.3.