atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's How many B channels on a PRI

I have 3 PRI's in the same trunk group.
There are 22 B channels on the first one, 20 on the second and 20 on the third.
Should there not be one A channel on each T1 and 23 B channels? It's been a long time since I worked on this stuff and I don't recall exactly how it all works.
I have an old G3siV11, not that it makes any difference.

A PRI should consist of 23 B (bearer) channels and one D (data) channel. There isn't an A channel. I'm a bit confused as to why two of your PRIs have only 20 channels though.

A PRI should be 23B+D (23 B Channels and1 D Channel), unless it's European format, in which case it's 30B +1D.

Sam

Beat me to it, Ed.

Sam

There wouldn't be a limitation due to the card in my Definity would it. Should I redirect this to the Avaya post?

With NFAS it might even be slightly better than 3 D channels, you could probably reclaim one and cut it down to 1D plus one backup timeslot for it.

Those terminate on a TN767 E board. Should I redirect these questions to the Avaya forum?

I have PRI's with 12,16, 20,and 23 B channels. It's popular down here particularly if you different trunk groups and just looking to save a few bucks with the cost of reduced B channels.

According to my AT&T Rep, we don't pay per B channel, just for the T1 ($645/mo). Not sure I understand that, in light of the short number of B channels I'm paying for.
I enailed him to find out why we aren't maxed out on B channels for the T1's and still have no response.

Enailed was an accident, I like it.