Sometimes, your phone can lose its connection to the call control system. When this connection is lost, your phone displays a message to let you know that this happened.
If you are on an active call when the connection is lost, the call continues. However, you do not have access to all the normal phone functions because some functions require information from the call control system. Your softkeys might not work as you expect.
When the phone reconnects to the call control system, you'll be able to use your phone normally again.
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