-=> Quoting Bo Simonsen to Leonard Erickson <=-

 BS> Hello Leonard!

 BS> 04 May 03 14:34, you wrote to Roy J. Tellason:
 
 RJT>> Leonard Erickson wrote in a message to mark lewis:
 
 LE>> But if run "raw" you can get rather better than 24 connections.
 
 RJT>> What does that mean?
 
 LE> Using the T-1 as a "raw" data pipe instead of
"formatting" it into the
 LE> 24 B channels and a D channel.
 
 LE> With 24B+D "formatting", you may only get 24*56k (1.344mbps) or at
 LE> most 24*64k (1.536 mbps).

 BS> The most normal is 30B+D, here in Denmark. Or 2B+D (normal ISDN).

Well, in the US the T-1 is defined as 24B+D.

 BS> But actually can one D channel handle so mutch? As far as i know isn't
 BS> it more than 9600 bps. I can see it's enought to handle signaling,
 BS> caller-id transfering, etc. But to 30B channels? 

Remember, the D channel is only needed for call setup and tear-down.
*During* a call, there's no signalling for that B channel. Well, maybe
if you've got Call Waiting, or the version that incorporates Caller ID
for the second incoming call. But even that only takes a small bit of data.

In some places in the US, in the early days of ISDN you could send data
over the D channel from your ISDN gear. Data *other* than the call
setup etc. 

I'm pretty sure about the 16k, as (for various reasons) the phone
company likes "even" numbers like that. I'd have to do some digging,
but I seem to recall being corrected by a telco engineer about that in
an echo or a newsgroup a while back when I said 9600. 


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