When you enable CNAM on a Local DID, we will update the telephone carrier authoritative database with your description/name. The actual CNAM lookup is performed by the called party, based on the Caller ID Number. As such, if you are not properly passing the Caller ID Number in your outbound calls, the CNAM lookup will not be able to occur. Additionally, if the called party does not have Caller ID enabled on their line, they will not see a "Name".
Please also note: By default, your UniTel SIP services do not set a Caller ID number for outbound calls through a SIP Trunk. Customers are required to configure their PBX system to send a valid Caller ID Number in all outbound calls. If outbound calls from your UniTel Trunk do not specify a Caller ID Number, your Trunk ID will be used in outbound calls. Customers can configure the trunk default Caller ID Number in their Dashboard under Settings > Manage Trunks