Avaya 1608 how to call foreign mobile phones?

1. Press the A key on the phone to enter the Avaya menu, then enter the network information menu, find the IP parameters, and set the IP number of the operator used. For example, the IP prefix of China Unicom is 1790 1. After setting, save and exit Avaya menu.

2. Dial directly through the dial of the phone, and the phone will automatically add the IP prefix.