[comp.protocols.appletalk] Phonenet

chris@eecs.nwu.edu (Chris Krohn) (11/05/88)

	Yes, Ethernet is a *much* faster physial layer for AppleTalk
and is the choice for high volume network traffic.  It is a relatively
expensive option, however.

	We have EtherNet, PhoneNet, and LocalTalk networks here, and
have found the least amount of trouble with PhoneNet.  In fact, our
LocalTalk cables have had a greater tendency towards deterioration
than PhoneNet.  (The rest of the net may have had different
experiences.)

	I would say that PhoneNet is probably a more economic
alternative.  Just make sure your end-users don't plug an actual phone
into your net :-).

Chris

MANAGER@SKIDMORE.BITNET (Leo Geoffrion) (11/06/88)

>Anybody out there used PhoneNet?  It's a third party (Farallon,
>Berkeley, CA) alternative to apple's LocalTalk.  Instead of
>Apple's expensive cables, it uses regular old cheap 4-conductor
>phone wire.  The little box that connects your machines to the
>network is also sold by phonenet, and is also cheaper.

>We're installing a network in our new offices.  Any reason why
>we shouldn't use the cheaper PhoneNet?  A couple retailers tell
>me it's just fine, they use it.  Apple does claim there cables are
>"85%" shielded.  So, what's the tradeoff, if any?

We've used both for two years, and can find no difference in performance.
Where differences exist, Phonenet is superior.

   1.  The RJ-11 connectors never disconnect accidentally (Unlike Apple's)

   2.  Phone cable is abundantly available in most institutions, and there
       are plenty of people who know how to handle it.

   3.  Phonenet's length limits are more generous.

As for the comment that TOPS on Phonenet is slow...   It's no slower on
Phonenet than on Apple's Localtalk.  We launch applications from it regularly.
We've run some benchmarks using the launch of MacDraw as a standard.  On
TOPS the time is variable, depending on the network traffic.  At best,(all
other machines idle), it's almost as fast as a local hard disk.  At worst
(several machines all trying to load applications simultaneously) it is
about as slow as a floppy disk.

Since our students are used to floppy disks, they don't complain about
slowness.  On the other hand, if you're used to a local hard disk (especially
the newer models with fast seek times, it is slow.

A couple of Phonenet cautions...

1.  Telephone technicians don't realize that Phonenet uses the yellow/black
pair (voice phones use red/green)  If a new line doesn't work, check that the
technician didn't omit the yellow/black pair.  Many do since it's useless on
most phone systems.

2.  Some phone techs like to install many spare lines.  for example, if you
ask for 4 lines into a room, they give you 25 (a standard cable size).  If all
are conected to the Phonenet, your phonenet will die.  While a phone system
can tolerate many dead-ended lines, Appletalk (all flavors) dislikes lines
with no equipment attached (probvably a source of cable reflections).  We
suffered through a couple of months of unreliable network performance until
we traced that problem down.

Incidentally, the local Apple Reps. recommend Phonenet over their own product
and actually use it in their offices.  How's that for a good recommendation :-)

PS.  I don't work for Farallon, nor do I get paid for endorsing them



===================================================================
Leo D. Geoffrion
Associate Director for             NYNEX:  (518) 584-5000 Ext. 2628
Academic Computing                BITNET:
Skidmore College                     MANAGER@SKIDMORE (for personal mail)
Saratoga Springs, NY  12866          LDG@SKIDMORE (for newsletters)

morgan@JESSICA.STANFORD.EDU (11/06/88)

steve@violet.berkeley.edu (Steve Goldfield) writes:

> PhoneNet is what we've got with our TOPS network. It works, but it is
> slow as molasses. You can transfer files across it and share a
> printer, but running applications is slow, slow, slow.  If you can get
> it, I'd recommend spending the extra to get an Ethernet network unless
> you have no conceivable need to run applications across the network.
> (I'd like to give others access to my database or to use my large hard
> disk to run things like hypercard and PageMaker. It isn't practical
> with PhoneNet, and I presume with Apple's cables either.

Steve's PhoneNet network may be too slow for him, but it is certainly
the case that a PhoneNET (or Apple LocalTalk) network can provide
acceptable transfer speeds to support all kinds of file service,
including complete diskless operation.  I know, I've used one that way
for many months.

Figure it out.  The raw speed of PhoneNET/LocalTalk is 230 kbits per
second.  Even if the effective throughput for file service,
considering packet headers, acknowledgements, etc, drops to 160 kbps
(and it's certainly possible to do better), that's still 20 kbytes per
second.  A small program like MacWrite or MacDraw could be loaded in 5
seconds, which is certainly not unacceptable.  A large program like
Illustrator could be loaded in 20 seconds, which isn't great, but both
times still beat using floppies.  In practice you'll be limited by the
workstation and server transfer speeds (on a Mac+, at least), not by
the network speed.

For the last year I've used a floppy-only Mac+ with access via
PhoneNET to a 3Com 3Server file server, which allowed me to have my 2
Mbyte System folder, 10 Mbytes of other files, and access to 20 Mbytes
of shared applications.  It wasn't as nice as the Ethernet-attached
MacII that dropped on my desk recently, but it was infinitely better
than floppies, and it was even better than having (only) my own local
20-Mbyte hard disk.  And there were 8-10 other Macs on the PhoneNET
and the server, too.

Anybody who says PhoneNET/LocalTalk isn't fast enough to support file
service for typical office applications is either a speed freak or has
never worked on a properly configured PN/LT.  Certainly it's possible
to install them in crazy ways that will still "work" but will have
terrible throughput.  Too many users will do you in, too.

By the way, don't even consider Apple LocalTalk.  PhoneNET (or its
growing number of clones) is better in every way.  Apple is reportedly
Farallon's biggest customer.  Nuff said?

(I have no connection with any of these companies other than trying to
get their salespeople to take me to lunch at every opportunity.)

 - RL "Bob" Morgan
   Networking Systems
   Stanford

han@Apple.COM (Byron Han, Architect) (11/13/88)

In article <Added.0XQtuBy00Ui3M7ck9F@andrew.cmu.edu> MANAGER@SKIDMORE.BITNET (Leo Geoffrion) writes:
>
>   1.  The RJ-11 connectors never disconnect accidentally (Unlike Apple's)

LocalTalk cables sold from Apple are now "Locking" LocalTalk cables which
provide significant protection against cables accidentally pulling loose.
Also, Kensington sells little plastic doodads that provide locking for
old-style LocalTalk cables.  They basically clip onto the cables and lock
them onto the transceiver.  They are cheap.  They are removable also.

This is not an official Apple statement or endorsement.  I have no connection
with Kensington.

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