Hello,

The audio issue you are running into is not directly related to the multiple registration factor, however it can introduce similar issues as you are experiencing -- depending on your network setup.

The user locations, or "registrations" you are seeing are solely informative as to where to send the SIP signaling and how to setup the audio path and essentially simply makes the phone "ring".

However the audio path is negotiated in this SIP signaling and transmitted in the initial INVITE and following 180/183 and 200 OK in an attached SDP body.

So my assumption without actually looking at any specific account would be that one of two things are happening:

1) Your registrations are not consistent and thus mis-informing of the proper required audio setup, i.e. one registration appears to be behind NAT, while the other does not, while as the public IP is still routing down to the device but effectively breaking the SDP signaling due to the incorrect NAT handling.

2) The audio ports being negotiated are simply just not passing traffic down to the device (each time a call is initiated a random port is selected in a range, i.e. 5004 - 65000 UDP).

The user location expiration is based off of the next registration interval. This way as a new registration is made, the previous registration expires.

Let me know if this helps clear the air a bit and if you have any further questions.

If you wish to PM me an example username I would be happy to further look into this and possibly narrow it down for you even further.