Applies To

Call2Teams - Customers


Callers may experience some delay in receiving ringtone back, when calling a Teams user.

Callers may also experience different ringtones synonymous with their call being moved between different systems.


The Call2Teams service has multiple POPs and SBCs that sit between the customer's PBX or Trunk and Microsoft. 

The signalling path carries the system messages back and forth over this network and the media is passed independently. 

We look at the signalling between Microsoft and our networks when analysing the routing of calls. 

However, firewalls and customers' own networks can and do add additional delays into the mix. 

As such, delays here are outside of our control. 

If there is a concern, compare the PSTN log from the Teams dashboard.  If this is provided when reporting a delay to us, we can compare it against our own logs.


Based on the point at which the media for ringtones is produced there may be a delay or change in ringtone whilst the call is being established. 

This is because Microsoft are providing the default Teams ringtone ahead of the instruction being overwritten by the PBX. 

The service is transparent in this process, in that we simply pass through these instructions without modification.