Yes, Snom M300 and M700 support the so called differentiated ringtone feature.

Based on this feature the PBX can distinguish between different type of calls (VIP, External, etc..) using the Alert-Info SIP header.

The handset will plays a melody depending on the Alert-Info SIP header value. The following table describes the supported header values and the associated melody.

Alert-Info SIP header
Alert-Info: <>;info=external
Melody 1
Alert-Info: <>;info=vip
Melody 2
Alert-Info: <>;info=friends
Melody 3
Alert-Info: <>;info=highpriority
Melody 4
Alert-Info: <>;info=lowpriority
Melody 5
Alert-Info: <>;info=blacklist
Melody 6

If "Remote Ring Tone Control" is enabled:
  • the ringtone received in Alert-Info will override the default melody configured on the handset under Settings -> Audio Settings

  • however, if the handset has a contact in the address book with a custom ringtone, the custom ringtone for this contact will override the ringtone received in Alert-Info

In case you need to disable this feature you can disable the Remote Ring Tone Control setting under the server  configuration (this setting is available since fw version 355B16):