Subject: Re: Clock synchronization with ISDN
To: Wolfgang Solfrank <ws@kurt.tools.de>
From: Christian Kuhtz <chk@gnu.ai.mit.edu>
List: tech-kern
Date: 02/17/1997 19:30:07
On Mon, 17 Feb 1997 20:22:18 +0100, ws@kurt.tools.de (Wolfgang Solfrank) wrote:
> > The timestamp is coming over the 16Kbit/s D channel, which is designed to
> > be a very low latency out-of-band signaling channel.
> >
> > Why would latency be high on the D channel? Assuming you're not abusing it
> > for something like a low volume X.25 channel, by definition, there should
> > never be any significant latency.
>
> Since by design the D channel may carry a "low volume" X.25 channel (it's
> running effectively as a 9600 baud X.25 line)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

And you are basing that assumption on what exactly?  Just because 9.6Kbps  
fits into 16Kbps, doesn't mean the X.25 PVC doesn't burst to the full 16Kbps.   
As you probably are aware of, you can very well run X.25 at full E1/T1 burst  
rate over an H10/H12 PRI.  9.6Kbps is just a traditionally common rate,  
nothing more.

--
Christian Kuhtz <ckuhtz@paranet.com> (work),   <chk@gnu.ai.mit.edu> (personal)
UNIX/Network Specialist,   "A German in the U.S., speaking for himself *gasp*"
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