04-16-2025, 08:07 AM
I recently upgraded two clients from 3CX v18 to 3CX v20. Both clients have their SIP trunks through the same, local provider (who I will not name). This particular provider uses a Metaswitch for their VoIP switching. One client had an issue whereby a call coming into their 3CX was then forwarded back out to a mobile phone or some other external destination, the caller ID would show up as "unknown" on mobile or "anonymous" on other devices. There was no rhyme or reason as to why one was working and the other wasn't with their SIP settings in 3CX being exactly the same (i.e. other than auth information, DIDs, etc. of course).
We tried everything in the SIP trunk options as to what was sent for caller ID info, etc. Eventually, the company was able to determine and make a change that resolved the issue. Apparently, it was set correctly on the one client that caller id on forwarded calls was working fine but not on the other one.
"IP address match required on the configured SIP binding." Apparently, that is a setting that is configurable on the Metaswitch and was stated to me "Apparently it elevates the client to a more trusted source level, even though it doesn’t bother to mention that in the documentation."
So, if you run into this issue, and your SIP trunk provider supports presenting the caller ID of the calling party on a forwarded call (for spoofing reasons, so providers won't do this), then this might be something to suggest to your provider IF they have a Metaswitch.
We tried everything in the SIP trunk options as to what was sent for caller ID info, etc. Eventually, the company was able to determine and make a change that resolved the issue. Apparently, it was set correctly on the one client that caller id on forwarded calls was working fine but not on the other one.
"IP address match required on the configured SIP binding." Apparently, that is a setting that is configurable on the Metaswitch and was stated to me "Apparently it elevates the client to a more trusted source level, even though it doesn’t bother to mention that in the documentation."
So, if you run into this issue, and your SIP trunk provider supports presenting the caller ID of the calling party on a forwarded call (for spoofing reasons, so providers won't do this), then this might be something to suggest to your provider IF they have a Metaswitch.