At 04:50 PM 6/25/96 -0400, John R. Sosebee wrote:
I'm seeing that also. I've been using ADC/Kentrox T-1 CSUs lately and they
come out of the box set for D4/AMI ... go figure ...
This is because most vendors still believes that T1 circuits are provision as D4/AMI..:-) Digital Link Encore csu/dsu by default has it setup as ESF/B8ZS.
Case-in-point: How many of you tried to figure out why the arrow keys only worked 50% of the time when you used a telnet session to configure a Digital Link Encore DSU / Ensemble shelf? And do you know what Digital Link did as a work around (ans: use the "U" and "D" keys for up/down).
Believe it or not I was the person who made Digital Link come up with the "U" and "D" keys ( don't forget the "L" and "R" for left and right keys). I had meetings with their Engineers to come up with this solution since we had problems telnetting to the csu/dsu through the Terminal Server due to very poor delay response using the arrow keys. It would take at least 5/6 strokes on one arrow key just to toggle it up/down or left/right. This still applies on the 3800 Digital Link Imuxes. John
This is because most vendors still believes that T1 circuits are provision as D4/AMI..:-) Digital Link Encore csu/dsu by default has it setup as ESF/B8ZS.
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. Anyone have experience mixing different vendor CSU/DSUs and getting things like remote loopback to work? Doug Hirsch <dhirsch@bbn.com> +1 617/873-2489 BBN Corp, 10 Moulton St, Cambridge MA 02138 USA
This is because most vendors still believes that T1 circuits are provision as D4/AMI..:-) Digital Link Encore csu/dsu by default has it setup as ESF/B8ZS.
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 channel/path. 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_. rob. p.s...I have the data sheet scanned in. I'm gonna html it.
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.
Ditto with the equipment I use from LARSCOM. Defaults are D4/AMI/RS449. The hardware itself seems just about bulletproof, however. Although the telcos seem to have never heard of it.
Anyone have experience mixing different vendor CSU/DSUs and getting things like remote loopback to work?
I don't recall having problems on T1's. I'm told that mixing vendor equipment on IMUXed multiple T1's is a recipe for disaster and therefore haven't tried to do it.
participants (4)
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Douglas Hirsch -
John Oliveira -
Mark M. Borchers -
rmg＠ranma.com