Recently I had a customer that wanted to setup SIP Trunks on their old phone system.
When I arrived onsite I realized that they were using an old T1 and not a PRI.
At first I tried configuring the settings in the GUI but that just created a mess in the config and didn’t work.
After some digging around I got it to work with the following settings:
interface t1 0/2
tdm-group 1 timeslots 1-24
no shutdownvoice trunk T02 type t1-rbs supervision wink role network
description “PBX”
connect t1 0/2 tdm-group 1
resource-selection linear ascending
did digits-transferred 4
modem-passthrough
t38
rtp delay-mode adaptive
codec-group Generic
The remaining settings are the same as a standard PRI.