Failed to Make a Call to an eSpace U1910 User as an IMS User

Symptom

When an IMS user makes a call to an eSpace U1910 user, the calling and called parties cannot hear each other when the called party picks up the phone. After a period of time, the calling party hears an announcement, indicating that the called party has powered off the phone.

Possible Cause

The IMS network does not support the update messages sent by the eSpace U1910, resulting in a call connection fault.

Solution

Step 1     Run the config coloring switch off command to disable the Ring Back Tone (RBT) service on the eSpace U1910 to prevent the eSpace U1910 from sending update messages.

Step 2     If the fault persists, contact the service provider.