Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!kwe
From: kwe@bu-cs.BU.EDU (kwe@bu-it.bu.edu (Kent W. England))
Newsgroups: comp.dcom.lans
Subject: Re: Cabletron Twisted Pair Ethernet
Summary: It works well
Message-ID: <28703@bu-cs.BU.EDU>
Date: 15 Mar 89 18:16:00 GMT
References: <1297@cunixc.cc.columbia.edu>
Reply-To: kwe@buit13.bu.edu (Kent England)
Followup-To: comp.dcom.lans
Distribution: usa
Organization: Boston U. Information Technology
Lines: 39

In article <1297@cunixc.cc.columbia.edu> 
chen@cunixc.cc.columbia.edu (Bill Chen) writes:
>I've seen notes bounce around about Synoptics Lattisnet, but has
>anyone had experiences (good or bad) with Cabletron's twisted pair
>ethernet product (MMAC-3)?
>
	We have had a lot of experience with Cabletron products.  We
have had the TP MMAC in a production environment for a month or so on
a very heavily loaded Ethernet with lots of nd and nfs traffic.  It
works well.
	We have one MMAC with three TPT-MIMs as they quaintly call
their modular interface cards.  Almost all the interfaces are used.
We have also tested their thin-coax MIM and the F/O MIM and FOTs.

	As many of you know, I like Cabletron very much, but I think
that all the TP Ethernet products are working well and will even
interoperate when the 10BaseT is finished and we have some production
chips for sale.

	One caveat:  We will not run TP Ethernet in 25 pair cable or
any other sheath with tip & ring.  One of our engineers has put the
Cabletron TP Ethernet thru a torture test of run lengths, multiple
punchdowns, tip&ring, etc and run LAN-MD tests and found no
appreciable errors.  It is designed to work in these existing cabling
environments, but we won't be installing it in anything other than
modern up-to-date individual 4 twisted pair circuits.  We designed our
cable plan with Ethernet in mind two years ago and I think it is
exceeding our expectations, but I caution others to have old cable
plants tested before making a major commitment to TP Ethernet.

	Following jbvb's exemplary etiquette  :-) I must mention
Synoptics, HP, Ungermann-Bass, David and probably many others who will
have proprietary and standard implementations of TP ethernet, all of
them with essentially the same performance.  (no flames, please)

	Now, if we can just get some 10BaseT onboard transceivers, the
economics should be just about right for this to really take off.

	Kent England, Boston University