What to do if Cisco Adapter ATA 190 does not register with Cisco Unified Communications Manager?
- SslyonsAug 18, 2025
If your Cisco Adapter ATA 190 doesn't register with Cisco Unified Communications Manager, first ensure that the adapter is connected to the Ethernet network and that the network is running. Also, check if the Cisco Unified Communications Manager or TFTP services are running, as all devices relying on it will be affected if it's down. Lastly, verify that the phone is receiving power.