Long cat5 run question

Will I be able to run a 200ft distance to another computer in another
building?
Suggestions on what type of router to get for this endevour would be
helpful.
It will be running outside. Can cat5 wire be buried?

Thank you


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> Will I be able to run a 200ft distance to another computer in another
> building?

100BaseT supports up to 330 feet. That's total distance, not line of sight.
So don't forget to take into account the lengths necessary to get from the
router, up/down the wall, over to the building exit, down/up the wall, under
the ground, etc, all the way to the other end. You'd be surprised how much
distance gets chewed up.

> Suggestions on what type of router to get for this endevour would be
> helpful.

If all you're doing is adding to the current subnet there's no router
needed. You can just hang another switch off the connection. Just don't
chain more than 3 switches. If you needed more than that you'd need to use
a router. How much traffic or how many computers are expected to be active
in the other building?

> It will be running outside. Can cat5 wire be buried?

Direct-burial jacket covered wire is available. Conduit is better as it
allows much better maintenance. But for inter-building connections it's
often common to use fiber optic cable. There are 100mb converters available
for the purpose, you'd use one on each end. Using fiber allows going longer
distances and avoids risks like lightning and surges. I'd much rather have
fiber in conduit that anything directly buried into the soil.

-Bill Kearney

"Bill Kearney" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) t...
>> Will I be able to run a 200ft distance to another computer in another
>> building?
>
> 100BaseT supports up to 330 feet. That's total distance, not line of
> sight. So don't forget to take into account the lengths necessary to get
> from the router, up/down the wall, over to the building exit, down/up the
> wall, under the ground, etc, all the way to the other end. You'd be
> surprised how much distance gets chewed up.

The spec actually states 100 meters being the max length which is 328 feet,
this includes all patch cables.

>
>> Suggestions on what type of router to get for this endevour would be
>> helpful.
>
> If all you're doing is adding to the current subnet there's no router
> needed. You can just hang another switch off the connection. Just don't
> chain more than 3 switches. If you needed more than that you'd need to
> use a router. How much traffic or how many computers are expected to be
> active in the other building?

Plug it into a switch or computer on each end. It doesn't have to be
anything special. But you might want to let us know what your doing just in
case further equipment is needed.

>
>> It will be running outside. Can cat5 wire be buried?

Yes, there are bury grade/outdoor cable available. I bought the last stuff I
used to put on a tower and between some buildings from www.wisp-router.com

>
> Direct-burial jacket covered wire is available. Conduit is better as it
> allows much better maintenance. But for inter-building connections it's
> often common to use fiber optic cable. There are 100mb converters
> available for the purpose, you'd use one on each end. Using fiber allows
> going longer distances and avoids risks like lightning and surges. I'd
> much rather have fiber in conduit that anything directly buried into the
> soil.

True, however there is nothing wrong with using cat5e cable if 10/100 is all
that's required. Fiber cable, the terminations and and media converters can
be pretty expensive. If i wanted gigabit speed i'd consider fiber for a run
that short other wise the cat5 will be fine, just all depends on what you
want to do and what you have planned in the future.

Adair

> The spec actually states 100 meters being the max length which is 328
> feet, this includes all patch cables.

Indeed. I've had runs slightly longer that worked, and ones shorter that
didn't. There are enough variables to make it reasonable to think of it as
a 300' limit. My point wasn't to quibble over the total limit, but to
stress that the distance needs to include ALL portions of the connection.
To the wall, up and over the ceiling, etc. If the other build is really
only 200' away then he's got plenty of distance to play with inside the
buildings.

> True, however there is nothing wrong with using cat5e cable if 10/100 is
> all that's required.

Two reasons I refuse to use ethernet wire buried: lightning and voltage
transients. If only because I've had personal experience with both wrecking
equipment.

> Fiber cable, the terminations and and media converters can be pretty
> expensive.

Not as expensive as the hassle of replacing fried equipment. I'd much
rather spend a few bucks on media converters instead of hundreds of dollars
on blown routers, switches and PC motherboards. But hey, feel free to
gamble.

> If i wanted gigabit speed i'd consider fiber for a run that short other
> wise the cat5 will be fine, just all depends on what you want to do and
> what you have planned in the future.

Yes, gigabit media converters ARE a lot more expensive. And quite probably
not worth doing in most situations. Heck, I'd probably go for bonding
multiple 100mb fiber links first. More often than not the network is not
the bottleneck. The host CPU, local disk drives, and processing times are
usually bigger bottlenecks.

-Bill Kearney

On Tue, 22 Jan 2008 22:24:29 -0500, "Bill Kearney"
<(E-Mail Removed)> wrote:

>> The spec actually states 100 meters being the max length which is 328
>> feet, this includes all patch cables.
>
>Indeed. I've had runs slightly longer that worked, and ones shorter that
>didn't. There are enough variables to make it reasonable to think of it as
>a 300' limit.

Nope. One of my fun demos is to take a 1000ft roll of CAT5, crimp
connectors at both ends, and connect it between my laptop and a Cisco
1900 managed switch. It won't do 100mbits/sec (100baseTX) in either
HDX or FDX, but will certainly do 10mbits/sec (10baseT) in either HDX
or FDX. The trick is to force the connection to 10mbits/sec and don't
let NWAY try to set it to 100mbits/sec. SNMP from the switch and
netstat shows no transmission errors. Thruput is also at wire speed
with FDX.

>My point wasn't to quibble over the total limit, but to
>stress that the distance needs to include ALL portions of the connection.
>To the wall, up and over the ceiling, etc. If the other build is really
>only 200' away then he's got plenty of distance to play with inside the
>buildings.

Yep. You're also correct about the extra cable for bends and turns.
I've gone over 300ft several times by forgetting about such details.

Note that the 100meter limit is between switches. You can add as many
ethernet switches as needed along the line to deal with regenerating
the signal. I've done 1500ft that way with 3 switches between
endpoints. I think that's about the limit as it was a bit flakey when
the switches got hot. I think (not sure) that the limit is set by the
end to end latency (delay), which causes ACK timing problems.

>Two reasons I refuse to use ethernet wire buried: lightning and voltage
>transients. If only because I've had personal experience with both wrecking
>equipment.

Sigh. We don't get much lightning in California, but the few
lightning bolts that hit a local tower managed to blow up most of my
media converters. Fiber works much better.

>Not as expensive as the hassle of replacing fried equipment.

The equipment is fairly cheap. My time to drive up to some mountain
top, with the wind blowing, rain falling, and lightning zapping, is
considerably more expensive. In retrospect, I should charge hazzard
or combat pay. However, if you wanna do gigabit fiber, the media
converters are VERY expensive. It's often easier to settle for
100mbits/sec and save your dollars until the prices drop.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS

"Bill Kearney" <(E-Mail Removed)> wrote in message
>> The spec actually states 100 meters being the max length which is 328
>> feet, this includes all patch cables.
>
> Indeed. I've had runs slightly longer that worked, and ones shorter that
> didn't. There are enough variables to make it reasonable to think of it
> as a 300' limit. My point wasn't to quibble over the total limit, but to
> stress that the distance needs to include ALL portions of the connection.
> To the wall, up and over the ceiling, etc. If the other build is really
> only 200' away then he's got plenty of distance to play with inside the
> buildings.

My point was not to piss over the actual distance, if you've had shorter
cables fail something was wrong with your termination or equipment. I
install and terminate cat5/cat6 cables daily and have never had a short
cable fail but we did have a customer that had us install 600ft of cat5e
against our will and it would not work.

>
>> True, however there is nothing wrong with using cat5e cable if 10/100 is
>> all that's required.
>
> Two reasons I refuse to use ethernet wire buried: lightning and voltage
> transients. If only because I've had personal experience with both
> wrecking equipment.

Not always possible for some applications say for traditional phone cabling
of course, as with anything standard grounding and bonding techniques needs
to be followed.
I agree that fiber is the way to go, it's just not cheap.
I just installed ST connectors on a 6 strand multimode fiber (12 total
connectors) for a customer who installed the cable themselves, still cost
them around $800 for my travel, connectors and test equipment. Lets add the
cost of media converters (around $100 each) and cable ($1 per foot?). Lets
not consider what connectors, and the termination and test equipment cost.
Our fluke DTX-1800 with fiber moduals was about $16,000 and our splice kits
were several hundred dollars. This is all assuming that someone has the know
how to install, terminate and test the fiber correctly.

>
>> Fiber cable, the terminations and and media converters can be pretty
>> expensive.
>
> Not as expensive as the hassle of replacing fried equipment. I'd much
> rather spend a few bucks on media converters instead of hundreds of
> dollars on blown routers, switches and PC motherboards. But hey, feel
> free to gamble.

Agreed

>
>> If i wanted gigabit speed i'd consider fiber for a run that short other
>> wise the cat5 will be fine, just all depends on what you want to do and
>> what you have planned in the future.
>
> Yes, gigabit media converters ARE a lot more expensive. And quite
> probably not worth doing in most situations. Heck, I'd probably go for
> bonding multiple 100mb fiber links first. More often than not the network
> is not the bottleneck. The host CPU, local disk drives, and processing
> times are usually bigger bottlenecks.

Right, that's my point, what does he need to do with this link? If it's one
computer or access point can he justify the cost of a fiber solution?
Reguardless
>
> -Bill Kearney
>

Jerff said:

> Note that the 100meter limit is between switches. *You can add as many
> ethernet switches as needed along the line to deal with regenerating
> the signal. *I've done 1500ft that way with 3 switches between
> endpoints. *I think that's about the limit as it was a bit flakey when
> the switches got hot. *I think (not sure) that the limit is set by the
> end to end latency (delay), which causes ACK timing problems.

The 802.1d standard says 7 (or it is 8?) intermediate
switches however that limit is for the Spanning Tree
Protocol and if you were not using redundant
paths managed by STP then there is no reason
to stick to it.

Of course you could use routers and add an arbitrary
number of hops. There are fewer now however at one
time it was not unusual for internet paths to have 25
router hops (and an unknown number of switchhops).

Each hop will add 2 x Transmission Delay to the
RTT. Say 2ms at 10M for full size packets.

On Jan 22, 9:11 am, "Bill Kearney" <wkearne...@hotmail.com> wrote:
> > Will I be able to run a 200ft distance to another computer in another
> > building?
>
> 100BaseT supports up to 330 feet. That's total distance, not line of sight.
> So don't forget to take into account the lengths necessary to get from the
> router, up/down the wall, over to the building exit, down/up the wall, under
> the ground, etc, all the way to the other end. You'd be surprised how much
> distance gets chewed up.
>
> > Suggestions on what type of router to get for this endevour would be
> > helpful.
>
> If all you're doing is adding to the current subnet there's no router
> needed. You can just hang another switch off the connection. Just don't
> chain more than 3 switches. If you needed more than that you'd need to use
> a router. How much traffic or how many computers are expected to be active
> in the other building?
>
> > It will be running outside. Can cat5 wire be buried?
>
> Direct-burial jacket covered wire is available. Conduit is better as it
> allows much better maintenance. But for inter-building connections it's
> often common to use fiber optic cable. There are 100mb converters available
> for the purpose, you'd use one on each end. Using fiber allows going longer
> distances and avoids risks like lightning and surges. I'd much rather have
> fiber in conduit that anything directly buried into the soil.
>
> -Bill Kearney

Isn't there an issue with the potential difference between the grounds
of the two buildings?

As Jeff points out you can 'abuse' the distances but need to make sure to
manually lock the port configuration. And have equipment that can actually
be configured to do this, many cheapie switches will not. To say nothing of
crappy drivers on various PC network cards. Know what your gear can and
can't do reliably.

> Note that the 100meter limit is between switches. You can add as many
> ethernet switches as needed along the line to deal with regenerating
> the signal. I've done 1500ft that way with 3 switches between
> endpoints.

I was a bit suprised to see the old 3-4-5 rule has less applicability
(none?) with switches. I'd still want to avoid stringing things along
through too many devices, if just to avoid debugging nightmares. But a
typical residential setting (or even a small office) isn't likely to run
into things like arp cache overflows and the like.

> Sigh. We don't get much lightning in California, but the few
> lightning bolts that hit a local tower managed to blow up most of my
> media converters. Fiber works much better.

At least the damage stopped there, not followed along the wire and to the
computers themselves.

-Bill Kearney

> Right, that's my point, what does he need to do with this link? If it's
> one computer or access point can he justify the cost of a fiber solution?

Yep, we're on the same page. It really does depend on what's really
necessary over the link.