How to make a transfer or conference call on Mitel 3300?

[x-man]

The only other option is Digital CO trunk.

[x-man]

 The Digital CO Trunk Circuit Descriptors form is used to assign signaling and timing parameters to groups of DS1 CO trunk circuits using channel associated signaling (CAS).

Use this form when performing the following tasks:

Program T1/D4 Trunks

Alternatively ask your T1 supplier what protocol you should be using for their T1  circuit.

[mghung123]

How about DID incoming? Using Digital CO Trunk Circuit may have problem to locate DID call.

[x-man]

Which is why I said to use the DID programming. I would vape all the programming for the lines and start from scratch after checking with your provider the required protocol just to make sure.

[mghung123]

Thanks, I need check my T1/D4 program step by step.