Telco discussions

>This is because most vendors still believes that T1 circuits are provision
>as D4/AMI..:slight_smile: Digital Link Encore csu/dsu by default has it setup as

I'm evaluating the new cisco 2524 with internal CSU/DSU, and it looks
like the default is ESF/B8ZS on this box too. Maybe there's hope for
the vendors catching up with reality on this front afterall.

I haven't touched a 2524 yet. Is the DSU options set on the command line?

Anyone have experience mixing different vendor CSU/DSUs and getting
things like remote loopback to work?

In-band and out-of-band lookpback codes should work fine. The differences
I've seen are with in-band codes. Some CSUs need to see the loop-up
code unframed, and some will respond to the loop-up code framed.

Rememeber that you can't send an out-of-band loop-up code unless
(a) you're ESF framed, and (b) the CSU is optioned to acknowledge
any o-o-b request.

An Out-Of-Band code is also known as an ESF code. The loop-up or loop-
down requests are sent in the 4kbps ESF channel instead of the actual data

Also remember that CSU and NIU (Network Interface Units) codes are
different. Make sure you're sending a CSU code. An NIU code is
technically called a Facility-2 code (FAC-2).

Since one mfgr's unit can't be configured to send a framed or unframed
loop-up/down (it doesn't tell you), you're at their mercy. Same if you
want to send an in-band or out-of-band code.

With a test set, though, I've never run across a CSU or NIU that I couldn't
loop up or down. You can virtually set a test set to do _anything_.


p.s...I have the data sheet scanned in. I'm gonna html it.