To Header formatting

I have a Soft Client registering to FreePBX through an Acme SBC.
Outbound calls work fine but inbound calls either from PSTN or from other extensions fail because the INVITE from the FreePBX to the client contains a cookie in the user portion of URI in the To header. Whilst this needed in the Request URI, using the registered contact point, I need the To header to just have the extension number in the user portion. Can I readily change this behaviour on FreePBX?
Essentially, on calls from the FreePBX to the extension, I need the To header to reflect the number number dialled and not just be a replica of the Request URI

No idea. The expertise on what is and is possible with the Freepbx supplied dialplan and configuration tools is at https://community.freepbx.org/

Can you give a concrete example, or otherwise explain what you mean by a cookie, as that is not a term used in the SIP specification.

Just tidying up/contracting some traces to avoid cluttering this thread…

This is not an asterisk solution, but have you considered using HMR on the acme to remove the uri-user param before sending the call to asterisk?

element-rule
name removeCookieParam
parameter-name cookie
type uri-user-param
action delete-element

  • Darrin