"6 wire" phone jacks.

[Philip Lewis]

So the local dollar store had some 6 wire (rj12?) dual port wall
phone jacks.

I was wondering if anyone knew off hand if the physical interface was
compatible with rj-45 plugs, and if the 6 wires were sufficient for
doing 10/100 networking. (I thought it only used 4 of the wires)

I have a temp network feed I want to put in and didn't want to spend
much on it and thought that might be a cheap solution.

Thanks!

--
be safe.
flip
Ich habe keine Ahnung was das bedeutet, oder vielleicht doch?
Remove origin of the word spam from address to reply (leave "+")

[Dan]

Philip Lewis wrote:
> So the local dollar store had some 6 wire (rj12?) dual port wall
> phone jacks.
>
> I was wondering if anyone knew off hand if the physical interface was
> compatible with rj-45 plugs, and if the 6 wires were sufficient for
> doing 10/100 networking. (I thought it only used 4 of the wires)
>
> I have a temp network feed I want to put in and didn't want to spend
> much on it and thought that might be a cheap solution.
>
> Thanks!
>
I can confirm that you only need 4 wires if you aren't going faster than
100mbps (this I am sure about).

As for the physical dimensions, from:
http://www.railwaybob.com/Modules/WiringRJ12s/RJ12s01a.html
-- quote --
# RJ45 is an 8-wire standard.
# The plugs and jacks are wider than their RJ12 counterparts - 7/16"vs
3/8".
# An RJ45 male plug won't fit into an RJ12 female jack.
# But an RJ12 male plug will fit into an RJ45 female jack.
# A lot of RJ12 female jacks are really RJ45 jacks in disguise! The
faceplate is an RJ12 faceplate but the jack part is really an RJ45
female jack.
# An RJ12 male plug (like the one on the end of your throttle) will
probably get stuck in this RJ45 female jack. It may also short across
the pins and cause you lots of grief!
-- end quote --

Hope that answers your question.

dan

[TCS]

On 07 Jan 2005 14:42:23 -0500, Philip Lewis <flip+spiced_ham@andrew.cmu.edu> wrote:
>So the local dollar store had some 6 wire (rj12?) dual port wall
>phone jacks.

Do you really want a househole where you have to always make a custom
cable to plug into the wall just to save a few pennies?

[Philip Lewis]

TCS <The-Central-Scrutinizer@p.o.b.o.x.com> writes:
>Do you really want a househole where you have to always make a custom
>cable to plug into the wall just to save a few pennies?
This was for a quick short term installation, and i have a plan for
using the jack for phone stuff later. (to split out DSL
filtered/unfiltered at the house entry point)

That and i was curious. ;)

Dan <haguru@gmail.com> writes:
>As for the physical dimensions, from:
>http://www.railwaybob.com/Modules/WiringRJ12s/RJ12s01a.html
Thanks dan, that was exactly the information for which I was looking.
Perhaps I'll drop a dollar as an experiment and see if it's one of the
rj45s in disguise. ;)
(although, iirc I counted the jack pins and only saw 6)

--
be safe.
flip
Ich habe keine Ahnung was das bedeutet, oder vielleicht doch?
Remove origin of the word spam from address to reply (leave "+")

[TCS]

On 07 Jan 2005 16:23:57 -0500, Philip Lewis <flip+spiced_ham@andrew.cmu.edu> wrote:
>TCS <The-Central-Scrutinizer@p.o.b.o.x.com> writes:
>>Do you really want a househole where you have to always make a custom
>>cable to plug into the wall just to save a few pennies?
>This was for a quick short term installation, and i have a plan for
>using the jack for phone stuff later. (to split out DSL
>filtered/unfiltered at the house entry point)

>That and i was curious. ;)

It'll probably work just fine. I really don't think those four unused
wires do much. "reserved for future use"

[wkearney99]

> So the local dollar store had some 6 wire (rj12?) dual port wall
> phone jacks. I was wondering if anyone knew off hand if the physical
interface was
> compatible with rj-45 plugs, and if the 6 wires were sufficient for
> doing 10/100 networking. (I thought it only used 4 of the wires)

Yes, they're RJ12 if all 6 connectors are wired, RJ11 if only two. The
physical profile on the connector is the same between RJ12 and RJ11. RJ45,
on the other hand, is a larger connector. The pin alingment inside an RJ45
connector is the same as an RJ12 with the added two wires being used as an
outside pair. Technically you can get away with plugging an RJ12 or RJ11
connector into an RJ45 plug.

You'd be better off not installing the RJ12 faceplates. They're not going
to be that much cheaper and you won't have to fiddle with oddball wiring.

> I have a temp network feed I want to put in and didn't want to spend
> much on it and thought that might be a cheap solution.

Ethernet networking won't just run on "any old wire". It's designed to use
CAT5 or better wire for several reasons, chiefly among which is the number
of twists the pairs are given along the cabling. Just trying to use old
telco style 6 pair *might* work on very short distances. Also be VERY
worried about whether or not that wire branches to any other telco
equipment. If you're "sure" it's point-to-point and you're not running it
for more than 10 feet total then it could be used for temporary purposes.
But honestly you'd be better served not screwing around with hacking
something together based on all the wrong components just because they're
cheap. The headaches that come later won't make it seems like such a
bargain.

-Bill Kearney

[Frank Stutzman]

wkearney99 <wkearney99@hotmail.com> wrote:
> Ethernet networking won't just run on "any old wire". It's designed to use
> CAT5 or better wire for several reasons, chiefly among which is the number
> of twists the pairs are given along the cabling.

Untrue. 10B-T Ethernet runs on CAT-3. Works better and tolerates more
installation vagaries on better wire. 100B-T is less tolerant of bad
wire. However, versions of 100 megabit ethernet has been run on barbed
wire (http://www.sigcon.com/Pubs/edn/SoGoodBarbedWire.htm) in a demo/lab
environment. Likewise for Gigabit ethernet
(http://www.wband.com/pressrm/05-23-02.htm).

My point is when you start taking about wire requirements for ethernet,
you need to be clear what sort of ethernet you are talking about.



--
Frank Stutzman
(a former employee of the former SynOptics Incorporated that was one of
the pioneers of twisted pair ethernet)

[wkearney99]

> My point is when you start taking about wire requirements for ethernet,
> you need to be clear what sort of ethernet you are talking about.

And coupling that that with oddball faceplates simply to save quite
literally a dollar or two is asking for more trouble that it's worth.

While it may well be possible to run 10-Base-Whatever over two cups and a
string the downside is long term maintenance and troubleshooting. If it's
crap wire and crap connectors you have an even harder job of debugging where
the problems lie. Reflectivity of signals along the wrong wire IS a
problem. But hey, penny-wise, pound-foolish....

[Frank Stutzman]

wkearney99 <wkearney99@hotmail.com> wrote:
> > My point is when you start taking about wire requirements for ethernet,
> > you need to be clear what sort of ethernet you are talking about.

> And coupling that that with oddball faceplates simply to save quite
> literally a dollar or two is asking for more trouble that it's worth.

> While it may well be possible to run 10-Base-Whatever over two cups and a
> string the downside is long term maintenance and troubleshooting. If it's
> crap wire and crap connectors you have an even harder job of debugging where
> the problems lie. Reflectivity of signals along the wrong wire IS a
> problem. But hey, penny-wise, pound-foolish....

I agree. Without a doubt. If it is a new installation, you should put in
the very best feasable. I did the wiring on the my house (new
construction). Spent the extra bucks and put in the best cat6 cable I
could find with appropriate connectors.

On the otherhand, my brother lives in a 1910 ranch house. During the last
remodel (sometime in early '90s) the house had a lot of cat3 cable put in
(somebody was looking ahead way back then). It was way cheaper to use the
existing wiring than it was to rip out the walls enough to get in CAT5.
It works and he's happy even though he's limited to 10 mbit. In his case,
I would have prefered a wireless solution, but he has a few specialized
devices that would have made wireless difficult.



--
Frank Stutzman

[~]

Exactly!


"Frank Stutzman" <stutzman@skylane.kjsl.com> wrote in message
news:crsgim$eou$1@stationair.kjsl.com...
> wkearney99 <wkearney99@hotmail.com> wrote:
>> > My point is when you start taking about wire requirements for ethernet,
>> > you need to be clear what sort of ethernet you are talking about.
>
>> And coupling that that with oddball faceplates simply to save quite
>> literally a dollar or two is asking for more trouble that it's worth.
>
>> While it may well be possible to run 10-Base-Whatever over two cups and a
>> string the downside is long term maintenance and troubleshooting. If
>> it's
>> crap wire and crap connectors you have an even harder job of debugging
>> where
>> the problems lie. Reflectivity of signals along the wrong wire IS a
>> problem. But hey, penny-wise, pound-foolish....
>
> I agree. Without a doubt. If it is a new installation, you should put in
> the very best feasable. I did the wiring on the my house (new
> construction). Spent the extra bucks and put in the best cat6 cable I
> could find with appropriate connectors.
>
> On the otherhand, my brother lives in a 1910 ranch house. During the last
> remodel (sometime in early '90s) the house had a lot of cat3 cable put in
> (somebody was looking ahead way back then). It was way cheaper to use the
> existing wiring than it was to rip out the walls enough to get in CAT5.
> It works and he's happy even though he's limited to 10 mbit. In his case,
> I would have prefered a wireless solution, but he has a few specialized
> devices that would have made wireless difficult.
>
>
>
> --
> Frank Stutzman
>

[TCS]

On Mon, 10 Jan 2005 00:00:22 +0000 (UTC), Frank Stutzman <stutzman@skylane.kjsl.com> wrote:
>I agree. Without a doubt. If it is a new installation, you should put in
>the very best feasable. I did the wiring on the my house (new
>construction). Spent the extra bucks and put in the best cat6 cable I
>could find with appropriate connectors.

Waste of money. The difference between basic cat6e and megabuck cable is
zero.

[wkearney99]

> On the otherhand, my brother lives in a 1910 ranch house. During the last
> remodel (sometime in early '90s) the house had a lot of cat3 cable put in
> (somebody was looking ahead way back then). It was way cheaper to use the
> existing wiring than it was to rip out the walls enough to get in CAT5.
> It works and he's happy even though he's limited to 10 mbit. In his case,
> I would have prefered a wireless solution, but he has a few specialized
> devices that would have made wireless difficult.

Well, this is where my comment about difficulties with debugging come to
bear. A number of new ethernet cards have a devil of a time being forced to
reliably work at slower data rates or half-duplex. This isn't much of a
surprise, but it is aggravating. Couple this with bad wire and you've a
recipe for real debugging headaches. That and undoubtedly someone will
'forget' about it being the wrong wire and even more time will get wasted.
As in, replacing the dead 10-Base-T hub when it dies with a 10/100/1000
autosensing cheapie switch and then wonder why the network became flaky.

The OP's question initial was about using the wrong wire and some cheap wall
plates. Both are bad ideas. Not because they won't work at all but because
they'll be a real problem down the road.

While the cost difference between one type of wire over another is negligble
you do raise a valid point about costs to rewire. Yes, it's a pain and the
cost is pretty hard to justify from the "it's just a home network"
perspective. But consider it's this sort of half-assed setup that
contribute to the many reasons people hate computers. Using the wrong stuff
on the cheap just always bites you, sooner than later. Trust me, I've tried
more times that I care to admit.

Anyway, if the wire is actual CAT-3 and it's installed in a star topology
(direct from the panel to EACH wall plate) then there's a reasonable chance
it will support even up to 100-Base-T on the distances found in most
residences. Just don't make the situation worse by using connectors, patch
panels, punchdown blocks or splices that aren't rated for ethernet.
Networks need more than just WIRE. They're not electrical signals like a
doorbell. The wrong wire ends up introducing all sorts of voodoo like
signal reflections.

-Bill Kearney

[Philip Lewis]

"wkearney99" <wkearney99@hotmail.com> writes:
>The OP's question initial was about using the wrong wire and some cheap wall
>plates. Both are bad ideas. Not because they won't work at all but because
>they'll be a real problem down the road.
Actually, it was using the right wire (cat5e) with the wrong faceplate
(rj12) though i didn't specify that at the time. (i stated that i
thought it only used 4 of the 8 wires, so some folks might have
thought that i was going to use cat3 instead of 2 pairs of the cat5e)

I responded to a post yesterday, but i don't see it, so i imagine i
must have emailed it to someone instead of to the group.

A Recap:
Wife gets new powerbook with airport extreme (802.11b/g(draft))
powerbook works fine on 802.11b network for 5 days.
Powerbook starts dropping 90-97% of packets
Works on the Apple store's 802.11b/g(draft) AP so they say my AP is
bad despite my AP working with 6 different 802.11b cards running on 6
different OSs. (Aerolink usb, SMC pcmcia, USRobotics pci and pcmcia,
an orinoco, and an airport (802.11b) running on the Mac 10.2, W2K,
WXP, W98, NetBSD, and Knoppix.... not respectively though)
Apple refused to run their network on 802.11b only mode.
(I suspect tech didn't know how to click the button on the airport
base station configuration panel... seriously)
I add hardwired connection for wife as a temp solution.
three weeks pass
Was going to run it through the basement instead of over the doorway
and underfoot, so I asked about the rj12 size compatibility.

this weekend, she unplugs the mac to walk it to the printer
(we reorganized that area and i didn't plug the printer into the print
server yet) and she receives some email over the wireless link.

A friend suggests the airport card might have needed to be reseated.
(of course we should *never* reseat hardware without doing proper
diagnostics first... right? ;)

so far the new mac seems to be working fine.

whee.

I still think i'm going to split the phone line into line1/2 at the
first junction in the basement into filtered/unfiltered DSL.

Anyone know a cheap source of 110 blocks?
Perhaps someplace with a block and punchdown tool combo?
(I have cat5e and rj45 ends/crimp tool already)

--
be safe.
flip
Ich habe keine Ahnung was das bedeutet, oder vielleicht doch?
Remove origin of the word spam from address to reply (leave "+")

[BruceR]

110 blocks can usually be found dirt cheap on ebay. Like $5 for a 300
pair. You can find the C4 clips and tools there too.

From:Philip Lewis
flip+spiced_ham@andrew.cmu.edu

> "wkearney99" <wkearney99@hotmail.com> writes:
>> The OP's question initial was about using the wrong wire and some
>> cheap wall plates. Both are bad ideas. Not because they won't work
>> at all but because they'll be a real problem down the road.
> Actually, it was using the right wire (cat5e) with the wrong faceplate
> (rj12) though i didn't specify that at the time. (i stated that i
> thought it only used 4 of the 8 wires, so some folks might have
> thought that i was going to use cat3 instead of 2 pairs of the cat5e)
>
> I responded to a post yesterday, but i don't see it, so i imagine i
> must have emailed it to someone instead of to the group.
>
> A Recap:
> Wife gets new powerbook with airport extreme (802.11b/g(draft))
> powerbook works fine on 802.11b network for 5 days.
> Powerbook starts dropping 90-97% of packets
> Works on the Apple store's 802.11b/g(draft) AP so they say my AP is
> bad despite my AP working with 6 different 802.11b cards running
> on 6 different OSs. (Aerolink usb, SMC pcmcia, USRobotics pci and
> pcmcia, an orinoco, and an airport (802.11b) running on the Mac
> 10.2, W2K, WXP, W98, NetBSD, and Knoppix.... not respectively
> though) Apple refused to run their network on 802.11b only mode.
> (I suspect tech didn't know how to click the button on the airport
> base station configuration panel... seriously)
> I add hardwired connection for wife as a temp solution.
> three weeks pass
> Was going to run it through the basement instead of over the doorway
> and underfoot, so I asked about the rj12 size compatibility.
>
> this weekend, she unplugs the mac to walk it to the printer
> (we reorganized that area and i didn't plug the printer into the print
> server yet) and she receives some email over the wireless link.
>
> A friend suggests the airport card might have needed to be reseated.
> (of course we should *never* reseat hardware without doing proper
> diagnostics first... right? ;)
>
> so far the new mac seems to be working fine.
>
> whee.
>
> I still think i'm going to split the phone line into line1/2 at the
> first junction in the basement into filtered/unfiltered DSL.
>
> Anyone know a cheap source of 110 blocks?
> Perhaps someplace with a block and punchdown tool combo?
> (I have cat5e and rj45 ends/crimp tool already)
>
> --
> be safe.
> flip
> Ich habe keine Ahnung was das bedeutet, oder vielleicht doch?
> Remove origin of the word spam from address to reply (leave "+")