Searching \ for '[OT] 10Base2 0r 10BaseT' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=10base2+10baset
Search entire site for: '10Base2 0r 10BaseT'.

Exact match. Not showing close matches.
PICList Thread
'[OT] 10Base2 0r 10BaseT'
2000\05\18@114155 by paulb

flavicon
face
Alan B Pearce wrote, and I just gotta add my bit :)

> 10base2 - requires coax to form network, one machine or connector
> faulty can take out whole network.

 Faulty connectors are the problem.  Some "Tees" sold are total junk.

 A faulty machine fouling the network is incredibly rare due to the
design and implementation of the interface to avoid this very problem
("Fail-Safe").  OTOH, a card that starts drivelling (continuously
sending) will trash *any* type of network with equal ease.

> Stiffness of coax and minimum length requirement between machines can
> make for a cabling headache.

 We talking thicknet or thinnet?  Given the latter, I'd forgotten
there was any minimum distance between machines.  Nevertheless, using
1.8m cables as minimum jumpers, this should be no problem.

> Also coax has a minimum bend radius to maintain its impedance
> integrity (read minimise network errors).

 About ¸".  Unless you bought rubbish co-ax such as solid centre-wire
used in wander leads, or just plain bad stuff.  I daresay it is out
there.  "Impedance integrity" isn't critical at 5 MHz (= 10Mbps) and
neither is total shielding - it basically means "don't crease the cable
so it shorts out".

> Limited to 10MBpS

 Not due to the cable by any means, it could be used up to 500 bps
quite easily.  The limitation is apparently the lack of driver chipsets.
FWIW.

 Troubleshooting 10Base-2 is, contrary to what is often said, dead easy
- you use a $15 digital multimeter and there's only two wires per lead!

 Unplug the "Tee" from the card and measure resistance across the
connector.  If it's 25 ohm plus or minus three, the "ether" is working.
If it's open circuit, it's probably a Chinese "Tee". ;-)

 If it's 50 ohms or a short, undo the Tee from the cables and test each
to find which is 50 and which is open or short.  Re-terminate the "good"
(50 ohm) end with the Tee and a terminator, back on the computer, and
you have restored at least that part of the network (OK, you need a few
spare terminators and Tees).

 Go to the next node you think the bad cable went to and test it.  You
have left the cable "open" (actually, if the fault was already an
"open", shorting it with an alligator clip would be better) so you will
be able to identify it at the next point when you repeat the procedure.

 You will end up with at worst, a bad cable and working network
segments to each side until you find a substitute and/ or repair the
cable.

> 10baseT - uses Category 5 twisted pair cable, requires some care
> fitting connectors, but can readily be run around a home to have
> machines in different rooms do to cable being more flexible.

 Work in fitting connectors is pretty much equal either way.  Wander
cables for Cat.5 are more flexible but fixed wiring isn't.

> No terminations required.

 Well, that saves just two!

> a cable fault takes out only one machine.

 That's the best point.  Unless it's the server of course. :)

> capable of 100MBpS, with higher rates being postulated (not likely to
> be a requirement for a home network).

> - Against - requires some form of hub, could be a multi port network
> card though the machine containing this would always need to be
> powered on for network to run.

 And there's the *big* "gotcha".  The hub, or more commonly, it's power
supply dies, and your *whole* network is trashed in one hit with no
ability to patch (except between two nominated machines if you have an
adaptor).  So, instead of keeping spare terminators and Tees, you *must*
have a spare hub and power supply and of course, tape over the power
switch.

 The problem with power supplies is that hubs are hungry, (8 watts or
so) and just on the safe borderline of "Wall-warts".

 I think most people (Myself and Mark for starters)) would say, for
small networks (five or less), 10Base-2 is more reliable unless the
cables are subject to abuse.

> For what it is worth, I would not go with base2 because of the problem
> with one connector being able to take out the whole network
> (voice of experience from dealing with company training rooms).

 Cables obviously subject to abuse.

 Do remember - for 10 Mbps, hubs should have BNC ports so you can use
both systems together to excellent advantage; co-ax for fixed segments,
and plug-ins for temporary.  This is what I currently use in fact.
--
 Cheers,
       Paul B.

2000\05\18@123601 by Michael Rigby-Jones

flavicon
face
One other point, ISTR that 10Base2 is half duplex only whereas 10BaseT can
use full duplex.  Not entirely sure on that though, anyone know for sure?

Mike

> {Original Message removed}

2000\05\18@195111 by Mark Willis

flavicon
face
Paul B. Webster VK2BZC wrote:
> Alan B Pearce wrote, and I just gotta add my bit :)
>
> > 10base2 - requires coax to form network, one machine or connector
> > faulty can take out whole network.
>
>   Faulty connectors are the problem.  Some "Tees" sold are total junk.

Agreed - My 10 cents worth on this topic:  I've had quite a number of
BAD "T"s, nowadays when I buy those I check for shorts across Shell to
Center pin (The most common failure mode I've seen), continuity of the
center pin to the other 2 ports I haven't seen fail (yet) but with only
about 50 "T"s, it's the next thing to check.

Favorite "T"s I use are the "F" style connectors MPJA.com sells - NICE!
You plug the male end (stem of the "F") into the NIC, and both coax
cables come out in parallel - FAR easier to route than a "T".  Migrating
to that for all 10Base2 machines here.

Second most common failure mode's when an 18 pound cat gets caught in
the CoAx, panics, and "Bolts", tearing the cable out of a connector
(almost took my fastest machine off a stand, once.)  Fix by replacing
the ripped up cable <G>

>   A faulty machine fouling the network is incredibly rare due to the
> design and implementation of the interface to avoid this very problem
> ("Fail-Safe").  OTOH, a card that starts drivelling (continuously
> sending) will trash *any* type of network with equal ease.

Never seen that happen, yet.

> > Stiffness of coax and minimum length requirement between machines can
> > make for a cabling headache.
>
>   We talking thicknet or thinnet?  Given the latter, I'd forgotten
> there was any minimum distance between machines.  Nevertheless, using
> 1.8m cables as minimum jumpers, this should be no problem.

Wire ties, folks.  <G>

{Quote hidden}

TEST the T first - test when bought.  Only cables I've seen with
problems were those torn by cat panic.  Fortunately my cats don't chew
cables!  If you have a Rabbit, get some 1/4" Hardware cloth between the
rabbit and the cabling...

>   Go to the next node you think the bad cable went to and test it.  You
> have left the cable "open" (actually, if the fault was already an
> "open", shorting it with an alligator clip would be better) so you will
> be able to identify it at the next point when you repeat the procedure.
>
>   You will end up with at worst, a bad cable and working network
> segments to each side until you find a substitute and/ or repair the
> cable.

I start from the server and work along linearly, test with a known good
old laptop with a PCMCIA NIC, when running new backbones here.

> > 10baseT - uses Category 5 twisted pair cable, requires some care
> > fitting connectors, but can readily be run around a home to have
> > machines in different rooms do to cable being more flexible.
>
>   Work in fitting connectors is pretty much equal either way.  Wander
> cables for Cat.5 are more flexible but fixed wiring isn't.

Best to hub "Clusters" of machines for home use, and 10Base2 down
hallways, unless you can install "cable trays", most landlords dislike
that idea <G>

> > No terminations required.
>
>   Well, that saves just two!

I don't find termination onerous at all <G>  Just keep spares...

{Quote hidden}

For 20+ machines with only 1 user (mainly_, I've been sticking with
10Base2;  Trying to cut down on my "hardware habit", does help that not
all machines are up at once usually.  Certainly, 10B2 is cheaper for N
machines (hubs cost money!)

> > For what it is worth, I would not go with base2 because of the problem
> > with one connector being able to take out the whole network
> > (voice of experience from dealing with company training rooms).
>
>   Cables obviously subject to abuse.

Never a problem here, except when I left it mis-routed where kitty could
get tangled in it...

>   Do remember - for 10 Mbps, hubs should have BNC ports so you can use
> both systems together to excellent advantage; co-ax for fixed segments,
> and plug-ins for temporary.  This is what I currently use in fact.

I'd suggest always having both if for no other reason than that a
visiting friend can hook to your LAN - otherwise you're "stuck" with
parallel port drives etc., for data transfers - Not "ideal".

> --
>   Cheers,
>         Paul B.

--
I re-ship for small US & overseas businesses, world-wide.
(For private individuals at cost; ask.)

More... (looser matching)
- Last day of these posts
- In 2000 , 2001 only
- Today
- New search...