[OpenSIPS-Users] Upstream gateway applying rport wrongly

[Michael Schloh von Bennewitz]

Hello list,

OpenSIPS 1.7.2
Solaris 11 AMD64

My OpenSIPS relays INVITEs from registered UACs to a upstream
gateway. OpenSIPS sends the INVITE over a random port. It listens
on 12.34.56.78:5060.

VIA RPORT

The upstream gateway writes the sending random port as
rport=<num-here> in the topmost Via of all replies as if
my OpenSIPS server were behind NAT (it's not though.)

When the upstream gateway sends new messages like reINVITE
or BYE, the RURI is like this:

  BYE sip:Username at 12.34.56.78:<rport-num-here>

OpenSIPS sees that the BYE has a totag and relays happily to
a port that's not listening, leading to 477 send failed.

QUESTIONS

How can I avoid getting the rport port number in the RURI?

Or what to do about it in the route block of the config?

Regards,
Michael