[SR-Users] Problem with requests routing when topoh is enabled

[Leonid Fainshtein]

Hi,
I have Kamailio 5.1 and I'm using the topology hiding module (topoh)
that is configured as the following:
modparam("topoh", "mask_key", "...")
modparam("topoh", "uparam_name", "....")
modparam("topoh", "uri_prefix_checks", 0)

Unfortunately Fanvil SIP phone modifies the remote party Contact's
URI before it puts it as R-URI in the re-INVITE request.
For example,
The remote party  Contact header:
Contact: <sip:127.0.0.8;tr=sr-O2Sdn60d3qrt3otz3o7L.6pF.6mUr6lF3qpd>

The re-INVITE request line:
INVITE sip:127.0.0.8;tr=sr-O2Sdn60d3qrt3otz3o7L.6pF.6mUr6lF3qpd;user=phone
SIP/2.0

As you can see, ";user=phone" was added. As result of that Kamailio
tries to send the request to 127.0.0.8.
If I disable sending 'user=phone' in Fanvil configuration then
everything works well.

I assumed that if uri_prefix_checks=0 then the topoh module should
take rid of such URI modifications. Am I wrong? Is there any way to
solve the problem except to modify the endpoint configuration?

Best regards,
Leonid Fainshtein