No dial tone refers to a situation where the light on the IP telephone is on and the display is working, but no dial tone is heard after the IP telephone goes off-hook. No dial tone occurs when:

• Connectivity between the media module and the IP telephone is interrupted.

• Insufficient DSP resources are available on the media module.

• Network Region configurations are incompatibly administered.

• Duplex administration results in a mismatch between the media module and the Ethernet switch.