My Snom desk phone is not using the correct ringtone for calls

Despite assigning contacts to specific groups and setting individual ringtones, the phone appears to ignore these configurations

In the example below, contact in the Friends group should play with ringtone 3, while contacts in the Work group should play ringtone 8 when a call comes in

In both cases, in our specific example, they both play ringtone 9 with an incoming call

Example

Debug 1

Two things can be looked into in this case

The first one is the phone's configuration for the ringtones based on the Alert-Info SIP header, as below

How to set different ringtones for internal versus external calls

As in the screenshot above, the ringtone 9 is used for calls coming in with an "alert-internal" Alert-Info header

Debug 2

Now you can check the incoming SIP INVITE to see if it has any specific Alert-Info header

If the SIP INVITE contains an header as the one below (or similar)

Alert-Info:<http://www.notused.com>;info=alert-internal

Then the phone can only see that call as an internal call, and that has priority on the group ringtone you've assigned to your contacts

Solution

To make the phone ignores Alert-Info headers and instead use its own contact or group-based ringtone settings you can clear the text values for all Alert-Info mappings as in the example below

With no matching text for Alert-Info, the phone will fall back to its internal ringtone logic and ignore PBX-provided values