I received a call from a customer asking for help in identifying a circuit that has an ID beginning with 36CSNA..... She thinks it is some kind of point to point circuit since two separate addresses are referenced on the bill for the same number. Does anyone have any idea what type of circuit this might be and what it might be used for?

The first 2 numbers are a Prefix. The CSNA is the Service Code and Modifier.

If the next sequence is more than 3 digits that is a serial number

OR if it is 3 digits...that is the NPA followed by /NXX/LINE If, I remember correctly.

It is possible the CS means Digital Cross System and NA is the Modifier.

HOWEVER... ¯\_(ツ)_/¯

Thanks, Dean. I'm very familiar with circuit ID components. I've just never seen one with the "CSNA" circuit identifier part, nor has my customer. They're paying a hefty monthly rate to Verizon for it in DC for an address that is less than a block away. I'm thinking it's old and abandoned (pre-IP) technology. Bell Atlantic toyed with a product they called "CO LAN" in the early 90s, and I think this might be a remnant of it.

Don't know if this will help Ed, I used to know this stuff, to damn old to remember, but this is what I found on the internet. I know it's a private line circuit, but that's about it. The 36 indicates a LEC ID.
CSNA
For AT&T Network Connection accounts. Select either CSNA (domestic) or CSNR (domestic and international) to trigger unique call processing. CSNA or CSNR cannot be standalone Subscribed Services on a TSG; either SDN or Toll Free Megacom must also be ordered with the CSNA/CSNR Trunk Sub Group.

The information was found here

Good catch, Bill!

Ed - If it's not red capped, have you thought about disconnecting it and see what happens? Or go to the other end and see if there's really something connected there....

Sam