From: pat@hprnd.rose.hp.com (Pat Thaler)
Date: Wed, 10 Apr 1991 00:27:59 GMT
Subject: Re: LAn on 50-conductor
Message-ID: <2230145@hprnd.rose.hp.com>
Organization: HP Roseville Networks Division
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hp-col!hpldola!hpysllb!hpyhde4!hpycla!hpcuhc!hpda!hpcupt1!hprnd!pat
Newsgroups: comp.dcom.lans
References: <1991Mar22.221831.17898@beach.csulb.edu>
Lines: 29

In comp.dcom.lans, cmilono@netcom.COM (Carlo Milono) writes:

    In article <1991Mar22.221831.17898@beach.csulb.edu> sichermn@beach.csulb.edu (Jeff Sicherman) writes:
    >
    >  Is it feasible to run a LAn sharing cabling in a 50-conductor telco-type
    >cable that is currently being used with a 1A2 phone system. What speed
    >limitations are there. ANy products more compatible with this than others ?
    >Any suggestions, critiques, experiences, etc. would be appreciated.


    10BASET was set to allow for such cable runs and is quite immune to any
    telephonic voltages, however, it is not wise to mix multiple LAN runs in
    a single 25-pair cable run due to interference with one another, but a
    single 10MBps works fine with 1A and 1A2 Key equipment, with a limit of
    100 meters.

Right on phone service, the 10BASE-T standard was designed to allow running 
in cables with analog phone services while meeting its bit error rate 
objective of less than 1 in 10^9.  The statement about not mixing multiple
LAN runs is not correct for 10BASE-T which was also designed to allow multiple
10BASE-T connections in the same bundle upto fully loading the bundle with
10BASE-T.  (Noise in a > 25 pair cable will be pretty much the same as 
in 25 pair.)

10BASE-T operates at 10Mbps.  The limitations of operating on twisted
pair are dependent on the total system design (encoding method, filtering,
equalization, etc) and not just data rate.

Pat Thaler