Cisco IP Phone 7821 do not receive call

[GilbertoNiño]

Hi everyone,

I have a incident with a Cisco IP Phone 7821. Actuallity the device do not receive any call.

I review from Cisco Call Manager Express and didn't found enable the option DnD (Do not Disturb) this feature is not enable from CME.

From the Cisco IP Phone do not see that the DnD is active, the device screan don't show me that the DnD is active.

In fact, the DnD function is not show enable from the buttons to active or deactive this function on device.

What can be the possible cause that the phone is not receiving calls?

Thank for your help.

[scoffman]

This sound like a configuration issue to me. Have you verified that the Phone and DN are configured to allow inbound calls? Is the phone added to the correct Device Pool? Do both the phone and the DN have the appropriate CSS? I believe the CSS on the DN will take precedence over the phone CSS. 

Is everything configured properly with the device pool? Does it have the correct region, and CUCM group?

Also, you don't mention if the inbound calls are local to the WAN, or if they originate externally outside the WAN? This could come into play with the "backend" Configuration too.