We have Lync server 2013 in our environment with Polycom VVX 310 and CX3000 IP Phones. We have issue in login on to CX3000, User are getting error message "sign-in cancelled due the internal error" but on same port with same user everything is working fine on VVX 310 IP Phones. Kindly suggest what I can do to fix the issue with CX3000 IP Phones.
We have tried connecting CX3000 through USB as well but no success
welcome to the Polycom Community.
The VVX phones in comparison with the CX phones have far more sophisticated method's of discovering VLAN's as an example using CDP,LLDP or even DHCP so you may not be able to compare them side by side.
Polycom and other manufacturers produce these optimized for Microsoft® Lync® devices after a reference design and the embedded OS running on the phones is provided, supported and maintained by our partner Microsoft®.
You therefore may want to reach out to the Microsoft® community and / or Microsoft® support directly instead as this is the most direct and efficient path.
Please try here
Alternatively your Polycom reseller who sold you the CX phone is your Tier 1 contact and can raise a Support ticket with Polycom for you if the unit is in warranty. If outside warranty there are other options as pay per incident.
Failing all the above you may want to work with your network team and setup a spanned port and simply compare the network traffic between the CX phone and the VVX phone.
If official support is required please check how to phone or open a case here----------------