Path: utzoo!attcan!uunet!cbmvax!vu-vlsi!nlp
From: nlp@vu-vlsi.Villanova.EDU (Nick Pine)
Newsgroups: comp.dcom.lans
Subject: Re: Ethernet bridges above 56Kb
Message-ID: <1760@vu-vlsi.Villanova.EDU>
Date: 25 Jul 88 17:54:44 GMT
References: <9392@dartvax.Dartmouth.EDU> <116@ernie.NECAM.COM> <7632@cup.portal.com>
Reply-To: nlp@vu-vlsi.UUCP (Nick Pine)
Distribution: na
Organization: Villanova Univ. EE Dept.
Lines: 15

Hi Andy!

Aydin Monitor Systems/Private Networks (215-646-8100) for whom I sometimes
work, also makes T-1 muxen. And of course Pine Associates, Ltd., soon to open
a Grenoble, France office, will design and build almost anything for an
extraordinary price :-). 

Nick

PS: I believe the CCITT T-1 frequency tolerance spec is +/- 75 Hz. or 50 ppm.,
    and most clock recovery circuits, which use resonant circuitry or phase-
    locked loops, would not work if you turned the clock down 50%. The easiest
    way to send arbitrary data and still meet the 1's density requirement is 
    to make every 8th bit a 1, and give up 12% of the bandwidth, or use "B8ZS"
    signaling, if available from the carrier.