FreeSWITCH

FS-6462 --resolve

I found a problem here but it may not completely match your expectations.
I reviewed the RFC 4028 and checked against the code and I discovered we should not be putting a Min-SE in any response at all besides a 422:

section 5:

   The Min-SE header field MUST NOT be used in responses except for
   those with a 422 response code.  It indicates the minimum value of
   the session interval that the server is willing to accept.

I corrected this problem and implemented the 422 response so if you request a value lower than the minimum specified for the profile.
If the value is equal or higher to the minimum, it will be reflected in the Session-Expires header in the response and no Min-SE will be present.