RJ25 to RJ45 for networking?

ToMMyGuN

Limp Gawd
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Hey! I just picked up 750 ft of what was advertised on craigslist as rj45 cable, but i got home and opened the box to find it is all RJ25 cable (used for running 3 phones off of one line). It was free, so no lost money woes, but it is frustrating!

My question is: Can i buy some rj45 connectors and crimp the wire to Ethernet standards? I looked up the pin out for cat5 cable and it looks as though only 4 of the wires are actually used in the cable.. I hate to throw all of this cable away.

Any thoughts?
 

krupted

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are they twisted pairs? if so, im sure it would probably work fine as long as the connectors actually do fit over the individual wires (i have no idea if they will). depending on the type of crimp connectors you use, you might want to squirt some hot glue into the back where the wire goes in once youre done, i have found that can really make things permanent when you dont have totally proper parts.
 

OmegaAvenger

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you can.. but dont expect to hit gigabit speeds ever, and you'll be lucky to get good connections at 100mbit.
 

criccio

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Just to clarify, this is CAT5 cable? The RJ25/45 is just the connector type and doesn't signify what type of cable it is.
 

krupted

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Just to clarify, this is CAT5 cable? The RJ25/45 is just the connector type and doesn't signify what type of cable it is.
i figure if theyre twisted pairs and they fit inside the rj45 connector it wont matter much what it actually is. it sounds like he found telephone cable...
 

OmegaAvenger

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i figure if theyre twisted pairs and they fit inside the rj45 connector it wont matter much what it actually is. it sounds like he found telephone cable...
yeah, it will work, if you don't care about the quality and reliability of the connection you can use plain old telephone cable.

to the OP: it sounds like you may have cat 3 cable, which will work, but likely not well. look and tell us if the cable has any markings on it.
 

gimp

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Just to clarify, this is CAT5 cable? The RJ25/45 is just the connector type and doesn't signify what type of cable it is.
this.

I can put an RJ-11 connector onto CAT5, but it's still CAT5.
I could also put an RJ-45 connector onto some CAT3, but it doesn't magically make it CAT5 :p

most likely very similar to CAT3, which is only good for ~10Mbps
 

krupted

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yeah, it will work, if you don't care about the quality and reliability of the connection you can use plain old telephone cable.
.
its free cable he got, i figured if it works at all its worth something. of course i wouldnt permanently install it anywhere, but for patch cables and short temp runs, heck i would use it.
 

TechieSooner

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I've done it before. Obviously your colors probably won't match the standard...
 

Vitamin_uk

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What a waste of time. CAT5e is hardly expensive. I would cut my losses buy the correct cable for the job.;)
 

horndog

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2 wires for transmit 2 for receive, the other 4 in CAT5 are for noise reduction. 3-pair is ok for short cables, not long runs. Do you have any firewood that needs bundling?
 

horndog

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Look it up.

For your basic connectivity 2 pairs are used, no one mentioned gigabit.

Do your due diligence.
 

criccio

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I know 2 pairs are used for 100Mb connections, common knowledge. Where did you read that the other 2 pairs are used for noise reduction?
 

horndog

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look it up, google UTP... Then google Shielded Twisted Pair.

The twisted pair reduces the noise reduction thus helps the signal from degrading.
 

OmegaAvenger

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look it up, google UTP... Then google Shielded Twisted Pair.

The twisted pair reduces the noise reduction thus helps the signal from degrading.
yeah.. by that they mean they twist the PAIRs used for the actual transmissio (TX +, TX -, and RX +, RX -)

The other 2 pair do NOTHING unless used in one 3 ways: gigabit ethernet, PoE, or if its used for phones (in which case you can do up to 4 lines) INSTEAD of data.

And I know this because I am a professional.
 

criccio

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^That is what I was getting at. The other 2 pairs don't do squat during 100Mb connections.
 

TechieSooner

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I think everyone would agree though, you'd be fine using that cable... Unless you're doing Gig.
 

TechieSooner

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unless it's CAT3, which is only good for ~10Mbps :p
I've ran 100mbps down CAT3 before, too :D
When you've got enough pairs, it's twisted enough to avoid crosstalk, and it's not a ridiculous distance, it's really not picky what you use.

Gigabit ethernet is obviously one area that you can't cut corners on, but I've been surprised what I've been able to make a working network link out of. Only thing I wasn't able to make work is a 200yard run underground on a bunch of phone wires... I had to resort to using a single pair and run it at 10mbps.
 

GotNoRice

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I recall talking with an engineer from HP years ago who was involved in building their ProCurve switches. He told me a story about when they were testing gigabit and had rigged it up so that they were using 4 rusted pieces of barbed wire as their ethernet cable, and still achieved gigabit speeds. I also helped run a LANparty for 5 years or so and the old, ghetto, busted-up, beat to shit ethernet cables we used never ever had any issues with gigabit either.
 

TechieSooner

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I recall talking with an engineer from HP years ago who was involved in building their ProCurve switches. He told me a story about when they were testing gigabit and had rigged it up so that they were using 4 rusted pieces of barbed wire as their ethernet cable, and still achieved gigabit speeds. I also helped run a LANparty for 5 years or so and the old, ghetto, busted-up, beat to shit ethernet cables we used never ever had any issues with gigabit either.
Yea, I 100% believe it. Obviously, there's going to be nobody surprised if it doesn't work, but you don't have to have the ritzy stuff to make things work... Just if you want to make SURE it works :D
 

krupted

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its good to see at least a few people who see the value in free cable. i used #6 AWG bonding cable in my car for my subwoofers. definitely not the 'proper' cable for the job, but works a treat of course. most people think all wire is specialized, but electrical copper is electrical copper, the insulation it has on it and the way its bundled is what makes the difference.
 

keenan

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Yea, I 100% believe it. Obviously, there's going to be nobody surprised if it doesn't work, but you don't have to have the ritzy stuff to make things work... Just if you want to make SURE it works :D
I don't...you'd need 8 pieces for GigE :p
 

TechieSooner

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I don't...you'd need 8 pieces for GigE :p
Yea I must've missed that little detail...
Regardless point is still proven though. Some "by the book" people would freak out if they heard I ran an ethernet signal down phone lines but... If it works, it works. How much more "wrong" it'd be to use barbed wire.
 

OmegaAvenger

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its good to see at least a few people who see the value in free cable. i used #6 AWG bonding cable in my car for my subwoofers. definitely not the 'proper' cable for the job, but works a treat of course. most people think all wire is specialized, but electrical copper is electrical copper, the insulation it has on it and the way its bundled is what makes the difference.
I am by no means saying the cable is useless. I'm just saying don;t be shocked if it doesn't work as well as expected.

BTW I have cut the ends off of old extension cords and used THAT for speaker wire.
 

ToMMyGuN

Limp Gawd
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Thanks to everyone for the discussion!

the wire is not twisted pair, and there is only 3 pairs of wire (it was used for data transmission at a national golf outing apparently). I don't think i am gonna invest the 25ish bucks to get a crimper and a 50 pack of rj45 connectors though. Not really worth the time.

Thanks again!
 

valve1138

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Sounds like it's just phone cable then.

Won't work for shit on any modern networking type stuff.
 

TechieSooner

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Sounds like it's just phone cable then.

Won't work for shit on any modern networking type stuff.
Not true, I've done it many times. LOL

Copper is copper is copper is copper. It's just once you get to a certain length crosstalk becomes so bad it won't work.
 

krupted

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I am by no means saying the cable is useless. I'm just saying don;t be shocked if it doesn't work as well as expected.

BTW I have cut the ends off of old extension cords and used THAT for speaker wire.
the only thing for speakers is they say to get all the high frequency detail its best to have many little strands of copper instead of a few thick ones like there are in power cable. they say the eddy currents on stranded cable are much higher therefore you get more detail. they say anyway... im not really sure how big a difference it is.
 

OmegaAvenger

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the only thing for speakers is they say to get all the high frequency detail its best to have many little strands of copper instead of a few thick ones like there are in power cable. they say the eddy currents on stranded cable are much higher therefore you get more detail. they say anyway... im not really sure how big a difference it is.
it was stranded though
 
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