[comp.protocols.appletalk] How long can a PhoneNet network be?

bin@primate.wisc.edu (Brain in Neutral) (08/18/90)

What's the maximum end-to-end distance a PhoneNet network can be,
and what factors does this length depend on?

Paul DuBois
dubois@primate.wisc.edu

awessels@walt.cc.utexas.edu (Allen Wessels) (08/18/90)

In article <2949@uakari.primate.wisc.edu> bin@primate.wisc.edu (Brain in Neutral) writes:
>What's the maximum end-to-end distance a PhoneNet network can be,
>and what factors does this length depend on?

(This is from memory.)  The total bus length limit is around 3000 feet, but
this assumes a particular wire gauge that I don't recall.  You might just go
buy one connector kit and read their manual.  It is a pretty good intro to
Mac networking and PhoneNet connector use.

One thing I would definitely recommend is that you know exactly where your 
wiring goes when you set your network up.  Some older buildings are not wired
so that you can use existing phone cabling to connect the network.

You can extended the total length of your network with repeaters and 
starcontrollers.  Lots of things cut down on the total length of the network.
Using LocalTalk connectors, mixing wire types, extended runs with modular wire
(the kind you use to hook the phone to the wall jack.)

- Allen

msm@energetic.com (Michael S. Maiten) (08/19/90)

> Date: 18 Aug 90 03:46:48 GMT
> From: bin@uakari.primate.wisc.edu  (Brain in Neutral)
> Subject: How long can a PhoneNet network be?
> To: info-appletalk@andrew.cmu.edu
> 
> What's the maximum end-to-end distance a PhoneNet network can be,
> and what factors does this length depend on?
> 
> Paul DuBois
> dubois@primate.wisc.edu

Funny you should ask; I just looked this one up yesterday! (However, I don't
have the manual in front of me, so this is from memory)...

For a daisy chain phonenet network, the maximum length is 1800 feet with 
24 nodes.  If you use a backbone net, then the distance is the same except that
you must reduce the total length by 4 feet for every 1 foot between the 
backbone jack and the phonenet box on the mac.  If you use wire (for the 
backbone) smaller than the normal gauge then the distance is reduced.

[This is from recent experience]:  If you have a phonenet network that is
too long, then you start getting intermittent behaviour.  The chooser may take
a long time to come up after selecting it, and then you may not see all the
devices you might expect.  If you leave the chooser up, you may see
devices (ie; set it to laserwriters) come and go periodically!  The solution
in this particular case was to reorganize the daisy chain phonenet to remove
unnecessary length; the problems then dissapeared.

------------------------------------------------------------------------------
Michael S. Maiten                 Internet:    msm@energetic.com
Energetic Systems                 UUCP:        ensys!msm
Telephone: +1 415 967-5538                     (...!sun!bridge2!ensys!msm)

ddaniel@lindy.stanford.edu (D. Daniel Sternbergh) (08/19/90)

In article <36336@ut-emx.UUCP> awessels@walt.cc.utexas.edu (Allen Wessels) writes:
>In article <2949@uakari.primate.wisc.edu> bin@primate.wisc.edu (Brain in Neutral) writes:
>>What's the maximum end-to-end distance a PhoneNet network can be,
>>and what factors does this length depend on?
>
>(This is from memory.)  The total bus length limit is around 3000 feet, but
>this assumes a particular wire gauge that I don't recall.  You might just go
>buy one connector kit and read their manual.  It is a pretty good intro to
>Mac networking and PhoneNet connector use.

The Farallon PhoneNET Connector User's Guide is one of the finest and
most useful pieces of technical writing I've ever seen, bar none.

Their "conservative guidelines" for normal LocalTalk speeds are as
follows:

Topology	22 gauge	24 gauge	26 gauge	Max # Nodes

daisy chain	n/a		n/a		1800 ft		24

backbone	4500 ft		3000 ft		1800 ft		48

3-branch
passive star	1500 ft		1000 ft		600 ft		16
(each branch)

4-branch
passive star	1125 ft		750 ft		450 ft		12
(each branch)

Beattie@SYSTEM-M.PHX.BULL.COM ("Art Beattie {AC602 862-4783}") (08/19/90)

>In article <2949@uakari.primate.wisc.edu> bin@primate.wisc.edu (Brain in Neutral) writes:
>>What's the maximum end-to-end distance a PhoneNet network can be,
>>and what factors does this length depend on?

As has been mentioned there are 2 basic styles of wiring; backbone and
daisy-chain.  This plays an important part in how far you can go with
the wiring.  By the way, all this is covered in the manual you get from
Farallon with a StarController; a good reference.

Backbone:

O----------O----------O----------O----------O----------O----------O
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
P          P          P          P          P          P          P

The "O"s are RJ11 telco wall jacks.  The wiring between them is one
UNBROKEN normal telephone hookup cable (2pair, only one pair is used.
The other pair is handy if the first pair used is broken or shorted).
The "P"s are the PhoneNet connectors from Farallon or TurboNet(ST)
connectors from Nuvotech.

Daisy chain:
_____ _____ _____ _____ _____ _____ _____
|   | |   | |   | |   | |   | |   | |   |
|   | |   | |   | |   | |   | |   | |   |
|   | |   | |   | |   | |   | |   | |   |
P    P     P     P     P     P     P    P

Each PhoneNet connecter can take 2 line cord connections.  Each
connection introduces a small break in the netowrk and thus a
discontinuity for the signal.  This reduces the effective distance the
signal can travel.  That is one reason why the backbone wiring is
prefered as long as the wire is installed without being broken.  The
installer's tool can be set up to punch down without cutting the wire.
And it is easier to use RJ11 wall jacks which have the punch-down style
connections internally rather than screws.

It is also important for the installers to realize that the LocalTalk
signals are of a higher frequency than what normal audio presents.  Our
installers used short cut technicques which will not work here.  If a
wire breaks, they used to wrap the wire around a punch down connection.
This type of connection will not support the frequencies of LocalTalk.

If it is necessary to reconnect broken wirings without stringing a new
one, the following is the best way we have found to work.  You first
remove the red and green wires (we don't mix voice and Localtalk on the
same cable).  Then carefully take the yellow and black wires from the
connector and punch them onto the connectors that the red/green wires
came from without breaking them.

              ___________________________
              |                         |
              |                         |
             zzz  zzz                   |
                   |                    |
Telco        zzz  zzz      ______       |     Continuation of
______________|    |_______|    |       |_________________
_______________    ________|    |       __________________
Cable         |    |       |____|       |     Telco Cable
             zzz  zzz                   |
                   |                    |
             zzz  zzz                   |
              |                         |
              |                         |
              |_________________________|

         |_________________________|
               RJ11 Wall Jack

Hope this helps.

CHARLES%uhavax.decnet@UHASUN.HARTFORD.EDU (08/20/90)

>To: info-appletalk@andrew.cmu.edu
> 
>What's the maximum end-to-end distance a PhoneNet network can be,
>and what factors does this length depend on?
> 
>Paul DuBois
>dubois@primate.wisc.edu

depending on the topology these are the maximum end-to-end distances
                     wire gauge (ft)
topology        22       24       26
daisy chain     -        -       600 
backbone      1500      1000     600
3 branch 
pasive star    500       333     200
4 branch
pasive star   375        250     150

this info comes from the Phonenet connector users guide

hope this helps

chuck richards
crichard@uhasun.hartford.edu
charles@hartford.bitnet