Cisco reccomends to replace that phones to the new models.
My customer plans for migration to CUCM12, but at this moment he has a few 7970 phones (~20) which are not supported. So the main question is it possible to register that phones as third party sip devices or any other way?
Theoretically yes, if you run SIP load on these you should be able to register as 3rd party SIP device keeping in mind that those do not support all of the features Cisco endpoints registered as Cisco devices do.
I've attempted this with one of the, perhaps more difficult phones, the 7912. The result so far is not great.
After successfully provisioning a SIP config file, upon the phone attempting CUCM registration this happens:
12751554.001 |10:47:00.766 |AlarmErr |AlarmClass: CallManager, AlarmName: DeviceTypeMismatch, AlarmSeverity: Error, AlarmMessage: , AlarmDescription: Device type mismatch between the information contained in the device's TFTP configuration file and what is configured in Unified CM Administration for that device, AlarmParameters: DeviceName:SEP001873A8C3ED, DeviceType:30007, DBDeviceType:336, AppID:Cisco CallManager, ClusterID:lab, NodeID:cm1,
Which reads that even though this model phone is not supported and cannot be provisioned as a Cisco endpoint, the fact that it presents itself as a Cisco phone blocks its registration attempt as 3rd party device.
If anyone has any thoughts on how to address, would be great. Otherwise, thought I'd share.