But by adding the suggested configuration to a Lync 2013 server as outlined in this article then the issue can be avoided and devices can be updated as needed.
When a Lync Phone Edition device is powered up and receives a successful DHCP lease it will look for the commonly used DHCP Option 15 parameter which provides a single .
Now that the certificate is fully imported, you must assign your Exchange services.
Right click on the new certificate under Exchange Certificates and select Assign Services.
Click the Download button in the pickup wizard to download your certificate files. If this root is present, delete the root from the list.
This article is a brief update to the process previously documented for Lync Server 2010.
In the import wizard, browse to the file downloaded in step 1 and complete the wizard to complete the certificate chain setup process.
You should see your Entrust Intermediate certificates listed in the Intermediate Certification Authorities folder.
The oldest tested version which could successfully register to a Lync 2013 server is 3.5.6907.187.
Attempts to use 1.0.522.x versions would always fail with As older versions of firmware may still be in use or come pre-installed on new devices then there may exist a scenario where the devices are unable to successfully sign-in to a Lync Server 2013 environment (specifically OCS 2007 RTM versions).