Subject: Re: Clock synchronization with ISDN
To: Ted Lemon <firstname.lastname@example.org>
From: Christian Kuhtz <email@example.com>
Date: 02/17/1997 19:26:02
On Mon, 17 Feb 1997 12:42:54 -0800, Ted Lemon <firstname.lastname@example.org> wrote:
> > Isn't ISDN signalling *slow*? If it's slow, then how much jitter is
> > that, and (at best) discretisation at the 9600-baud D channel line speed
> > adding? Not to mention switching delays inside the telecom net?
> Furthermore, aren't the 2B and the D channel really multiplexed over a
> single serial channel?
That depends on how you look at it, since there are a variety of different
perspectives possible; as you possibly are aware of, ISDN is a fairly complex
For our purposes, no, they're not multiplexed in such a way that one takes
priority over the other and can force traffic to be delayed based on traffic
on the other two B channels in case of a BRI. The latency for 16Kbit/s D
channel traffic is constant latency, no matter what happens with the two
64Kbit/s B channels. Even if they end up going through the same pipe.
Christian Kuhtz <email@example.com> (work), <firstname.lastname@example.org> (personal)
UNIX/Network Specialist, "A German in the U.S., speaking for himself *gasp*"
Paranet, Inc. Rocky Mountain Branch, http://www.paranet.com/ MIME/NeXTmail Ok