Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!iuvax!uxc!uxc.cso.uiuc.edu!uxg.cso.uiuc.edu!uxa.cso.uiuc.edu!jsa00564
From: jsa00564@uxa.cso.uiuc.edu
Newsgroups: comp.dcom.lans
Subject: Re: Lattisnet/Ethernet over Twisted Pai
Message-ID: <114400002@uxa.cso.uiuc.edu>
Date: 24 Feb 89 00:39:00 GMT
References: <98@cs.columbia.edu>
Lines: 74
Nf-ID: #R:cs.columbia.edu:98:uxa.cso.uiuc.edu:114400002:000:3205
Nf-From: uxa.cso.uiuc.edu!jsa00564    Feb 23 18:39:00 1989


howard@cos.com writes:

>..the twisted pairs, in the eventually working condition, 
>went through 2-3 wire closets containing 66-type punchdowns and/or
>RJ45 patch panels.  As long as the pairs were kept together, everything
>worked..
>
>In the original comment about Lattisnet, would the above wiring close
>arrangement be a problem, assuming puchdowns, etc., are done properly>
[stuff deleted]
>Does Lattisnet really need a continuous wire which does not go through
>wire closets (with the caveat that these closets are wire by competent 
>data installers as opposed to general voice people.

a couple comments I can make here.....

1. No, Lattisnet does not require a "straight-through" cable with no 
   punches.  BUT, the punchdowns are the source for problems, and should
   be minimized whenever possible (without bypassing good practice)

2. At my installation, we have workstations connected 360 feet away, and
   they go through 3 wire closets by the time the wire gets to the 
   concentrator (hub of the star topology).

3.  As I stated before, I was able to simplify the installation and
    conform to "telephone standards" by converting the Lattisnet RJ45
    for use with RJ-11 jacks.  Since Lattisnet only uses 4 wires (2-pair)
    the other 2-pairs in an RJ45 are unused.  I had Black Box construct
    cables to make the switch.

**  Things to check if a workstation can't connect to a file server  **

This is my basic checklist for diagnosing Lattisnet cable problems, without
the use of Sniffers, etc.. (assuming the PC/NIC are good)

    --  If the workstation is plugged in, and the wire is the correct 
	one, a green light will appear on the NIC and the Concentrator.
	This light shows ONLY that at least one wire of each pair is
	connected. Getting the green light (Link Status) is only half
	the battle.

     -- Be sure all strapping/jumper wire used in the phone closets are
	true solid-core, twisted pair.  No exceptions.

    -- Check for obvious bad punchdowns.  Repunch all with a SHARP TOOL!

     -- If it still doesn't work, re-punch each block, starting at the
	furthest connection from the PC (where it's most sensitive).

     -- Tighten all clips on 66-type blocks.  Replace any that don't seem
	to fit snug.

    -- Lastly, the workstation, if it still doesn't work, is probably
       more than 360 cable-feet from the concentrator. Install a Link
       extender, or find another wire path.... (I know this is vague)


By the way, my conversion to RJ11 jacks allowed me to use our "general voice
people" to install Lattisnet nodes, without any special training.  The only
portion of the wire installation that is different from a phone extension is
that Lattisnet's host module (MOD-407) block skips one pair between nodes...


E-mail any questions...
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Jeff Autor
jsa00564@uxa.cso.uiuc.edu		"Help me! I'm an engineering student!"
at the University of Illinois

(also affiliated with Valmont Electric, a subsidiary of Valmont Industries)
The opinions are my own and not necessarily those of Valmont Electric.
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