Network Cable

[rory 0]

How many pairs of the 4 pairs in a Cat5 cable, are required for the network for a router, does it use all 4?

 

Rory

[qman 0]

I think that it only uses 3 pairs, but I'm not too sure.

[CCTVINSTALLER 0]

Rory i think it uses only 2 pairs, orange and green. Im pretty sure about that, because i remember doing an installation and not connecting the blue and brown to the patch socket and it worked fine, but that was connecting one comp direct to another, should be the same with router. Another way i know is that when you make a crossover over cable, you only switch the orange and greens pairs around- transmit and receive. Best way is to try it out, i think the structure of a rj45 socket is:

 

1. white/orange

2. Orange

3. white/green

4. Blue

5. White/Blue

6. Green

7. White/Brown

8. Brown

 

Crossover is the same except 1= white/green, 2=green, 3=white/orange, 6=orange, cut the blues and brown and see if you get any signal.

[rory 0]

ok thanks guys, ill probably stop by the guys im going to get to crimp it anyway. Reason is Im limited to a certain amount of pairs as we ran 4 cat5 cables and silly me though that meant 5 pairs per cable!!!

[C7 in CA 0]

CCTVINSTALLER is absolutely right. The one thing I would add about the crossover cable that may not be obvious to those who don't work with Cat5/6 cabling much is: you only switch ONE side. So...

 

1= white/green, 2=green, 3=white/orange, 6=orange on one end and

1= white/orange, 2=orange, 3=white/green, 6=green on the other.

 

If you switch both ends then you are back to a straight through cable

 

Rory, Cat5 as you probably know is short for Category 5. It is a wide scope standard that specifies a lot more then just cable properties. It outlines (among other things) proper installation techniques like maximum bend radius, max. pulling tension, cable support structures, Cable testing standards (I use a 9 thousand dollar cable certifier) and so on right down to labeling faceplates. If you don’t follow any one of the “Standardâ€

[rory 0]

ok so I only need 2 pairs for the network?

 

Because barrier strips are easier to find here than punch blocks. on the 2nd building (remote side) im using barrier strips, maybe, havent got them yet, may see if I can still get my hands on a punch block .. anyway, lets call this the remote Junction -- building 2 - this junction carries all the building 2's alarm, cctv, phone, and network cabling back to building 1 - the main building. There are 4 cat5 cables. Power is local for both buildings for alarm and CCTV. So I only need:

 

CCTV = 5 pairs (5 cameras)

 

Alarm = Keypad Data (1 pair), Zone Expander(Polling loop) (1 pair), Sirens (1 pair) = 3 pairs

 

Phone = 1 pair (phone system extension - may be 2 pairs)

 

Network = 2 pairs (?)

 

total available = 4 x 4 = 16 Pairs

 

total used = 11 pairs

 

total left = 5 pairs

 

I may want a monitor for the cameras from building 1's cameras at the office in building 2 as well, so that will take up an extra pair if we use it. And adding an extra camera would take yet another pair, so we'd have 3 pairs left give or take for the phone or as extra. Dont think there would be anything else required.

 

So just to confirm 2 pairs for Network to connect a router to a remote hub in building 2?

 

thanks

 

Rory

[C7 in CA 0]

Yes two pairs. And I would specifically use the orange and green pair from the same cable. The orange and green pairs twist rate was probably optimized to carry the send and receive signals.

 

But it looks to me you could put the Ethernet on it's own cable and still have your extra pair for the monitor. Then in the future if you need pairs you can worry about affecting the network connection. Becuase the barrier strips could degrade the signal substantially. Be prepared. You may have to settle on 10Mbps.

 

Have you settled on which services you are going to share with which cables?

[rory 0]

Yep, you are correct, Ill probably end up leaving 2 Cat5 cables for them anyway, 1 for Network and 1 for phone, and they can have their people deal with that. The client may not even want the extra camera or monitor right now anyway, I was just thinking out loud

 

Would a Punch Block be better then? I can look a little more, here you gotta kind of drive all over the island looking for this stuff as no sales people know what it is .. same with most electronics here ..

 

what do you mean by services? Phone, alarm, CCTV?

 

Rory

[C7 in CA 0]

Yep, you are correct, Ill probably end up leaving 2 Cat5 cables for them anyway, 1 for Network and 1 for phone, and they can have their people deal with that. The client may not even want the extra camera or monitor right now anyway, I was just thinking out loud

 

Would a Punch Block be better then? I can look a little more, here you gotta kind of drive all over the island looking for this stuff as no sales people know what it is .. same with most electronics here ..

 

what do you mean by services? Phone, alarm, CCTV?

 

Rory

 

 

A Cat5 rated 66 block would probably be better. But what kind of cable are you using within the building? Remember you can't terminate stranded wire to a punchdown block. If you are simply leaving the network guys a loose Cat5 cable just for them then the other services: Phone, alarm, CCTV will probably do just fine on terminal strips. Didn't I read somewhere the camera baluns can even use Cat3 cable? Cat 3 is way more tolerent then Cat5.

[rory 0]

It is all Cat5 cable. One of the alarm wires is Telco 2 pair wire, not stranded.

Ill check and see what I can pick up here. I may be able to get it from a local computer store also.

 

Thanks

 

Rory