Hi!
You can use either one of the following methods to configure the IP phone linkage:
1. Method 1:
When adding an SIP user, set IsJoint as YES. When adding a UC account, set the Service number to the associated SIP number.
2. Method 2:
When configuring the number allocation policy, set IsJoint as YES. When adding a UC account, set Number allocation policy to the linkage policy and the Service number to the SIP number to be associated.