I need to make some T1 cross over cables

This Google search for how to make T1 cross over cabless eems to show several ways to do it.
do you just pick one and go with it, is there an industry standard, or a best practice.

https://www.google.com/search?q=image+results+how+to+make+a+t1+crossover+cable&hl=en&prmd=imvnsfd&tbm=isch&tbo=u&source=univ&sa=X&ei=FH0iUKnDOOmK6gG3qoCYDA&sqi=2&ved=0CGMQsAQ&biw=1113&bih=860

T1%20Crossover.jpg

t1 cross over.jpg

568A-568B t1 crossover.gif

t1-crossover3.jpg

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Comments

NetworkVeteran

All the images I saw on the Google link you posted showed wire 1:4 and 2:5 on both sides.

Best practice? Buy a cable, don't make one.

(Engineer-hours cost too much.)

drkat

yeah but buying it and shipping it takes longer than making one

inscom.brigade

NetworkVeteran wrote: »

All the images I saw on the Google link you posted showed wire 1:4 and 2:5 on both sides.

Best practice? Buy a cable, don't make one.

(Engineer-hours cost too much.)

1.) currently not employed
2.) 1:4 & 2 : 5 ; on a flat cable, OK | on a round Cat5 [?]
I should have stated: I am not making them from flat console cable. I have a roll of Cat5.

if both side are the same how is thatr a t1 crossover 1:4 2:5 on both sides?

I make all my cables while i am reading, i don't just sit and make cables.

networker050184

It doesn't matter if you are using flat cable or not, the numbers are for the pins in the connector.

inscom.brigade

networker050184 wrote: »

It doesn't matter if you are using flat cable or not, the numbers are for the pins in the connector.

OK iam concerned with the rj-45 connector pin 1:4, & 2 : 5 only, fine

we were taught that the unshielded twisted pair has different amount of twist per foot for each color group. If you strip away the cover, not disturbing the factory twist layout you see this is true. If you unwind to much you have lowerquality, if you make up your own color layout you have lower quality.
are we essentialy saying pick any diagam you like advertised as a T1 crossover and go with it?

img17.jpg

networker050184

I'm not too sure on the amount of twist involved. Any color coding should work especially in a lab.

drkat

Guess I'll chime in here.

Lets forget about the term T1.. the fact is the pin outs are different for T1 signaling than Ethernet. Your amount of twists aren't going to be affected, you're going to make this cable just like you would a Ethernet cable - the only difference is the pin out will be different. Lets not forget.. that when a T1 comes into the NIU the signal is boosted and sent on its way.. The only time you should be concerned with signal quality is if you're demarc is extended and how the NIU is programmed (hot or cold). You can actually run T1 cables with Cat 3 so dont worry about the twists..

T1 pin out is: http://www.cisco.com/en/US/customer/products/hw/routers/ps274/products_tech_note09186a00800f9d37.shtml

1

RX ring

2

RX tip

3

Not Used

4

TX ring

5

TX tip

6

Not Used

7

Not used

8

Not used