[Serusers] Need a way to delete a URI parameter if present from the INVITE

[Frank Durda IV]

A given system is sending me INVITEs of the form:

INVITE sip:6663338888 at 111.222.33.44;cic=9876;rn=6663331212;npdi SIP/2.0

that includes some URI parameters, eg the things after the semi-colon.

In this case, the cic=nnnn value is really some internal routing
number and not a real PSTN CIC value (like 0288 for AT&T).  So
when this eventually reaches a switch on the PSTN, that switch
sees that someone has already determined the CIC and it
attempts to route using what really isn't a CIC at all.

I would like to strip this "cic=nnnn" out of the call
within SER, and while there are a number of documented
rewriteuri functions for altering the URI in SER, there
doesn't seem to be anything that can be used to get at
URI parameters.  For the above, I would like to trim it to:

INVITE sip:6663338888 at 111.222.33.44;rn=6663331212;npdi SIP/2.0

as the rn= and npdi values are sane and can be used by the
destination switch.

Is there such a beast, or is the only options to add a function/module
or use the exec to invoke an external program to do the job?

Thanks in advance.