We had a similar problem on a recent project where were integrating soundpoint 331 and other version on cucm 10.5 nothing that we tried worked until we upgraded the firmware of the Polycom phone. Yes you can configure polycom phone to register from t...

i have a similar problem. Polycom phones of the same version with the same configuration one is working the other is not working. the non working one is not exchanging the digest credentials with the CUCM. All the phones have software versions below ...