SIPStation and FAXStation - How does Digium SIP Trunking determine Caller ID name on outgoing calls?

If you are using Digium's SIP Trunking:

You will need to contact Digium Technical Support to update the CNAM database with the Caller ID Name you wish to use.

When a call is sent out through your Digium SIP Trunk, the upstream provider will do a Caller ID Name search based on the Caller ID Number that is being sent.

They do not look at the Caller ID Name that we send in the header information of the SIP INVITE packet.

When you have a Digium Technical Support Engineer create Outgoing Caller ID Rules, you will want to use a DID you own as the Caller ID Number or the Caller ID Name will show up as name unavailable.

For example, a customer does not want to have a DID associated with some outgoing calls because they do not want called parties to callback the Caller ID Number afterhours.

The user has Digium create an Outgoing Caller ID Rule sending 0000000001 as the Caller ID Number, when the outbound call is placed, the Caller ID Number will pass, but the carrier will do a search based on that number and not find a name connected to it.

The workaround would be to use a Caller ID Number that you own with Digium and if someone calls that number back, route it to an IVR that explains business hours and the correct number to dial, and hangs up.