1. ## Network Cabling

Anyone on the list a network guru? I have a study over a garage and being a new build all the reflective stuff in the insulation means a feeble wireless signal. It's also on a separate electrical circuit. There is a Cat 5 cable running between the two and according to the test meter, all the right bits are connected. The computer will detect the network, then drop it within a second. The cable run is about 30m and there are two junctions. 1 is a junction box in the Garage, the other is by the BT box (it originally was wired for only a phone). I can only assume its a connection issue, but all the connectors (scotchlok UR2) look good. IS is too many junctions?

I'm thinking I need to re thread a single cable run.

Networks are one step away from wizardry for me so, HELP!

2. When you say there are three connection points, do you mean three sockets on one cable?

If so then this isn't ideal and you'd only ever be able to use one at a time!

3. Sorry for the confusion. One cable run to a junction box, each wire within the cable then connected to it's correct colour on the next cable run (underground) to the next junction box (again each coloured wired connected up to its colour) that then runs into the house and into the modem.

4. Buchan,

hopefully we'll chat later this week and get it sorted. Data transmission is different to voice or electrical transmission as it relies on more than just an electrically conductive circuit. There are 8 strands of wire all twisted togeher in a Cat 5 cable and if you untwisted them all, they'd all be different lengths, the purpose being that the kit that sends the signal down the wire sends the signals at different speeds down each strand so that they all get to the other end in the correct order depending on the length of the strand it is sent down. As soon as you put something like a junction in the way, let alone three of them then you're asking for trouble.

Anyway, I'm sure we can get it sorted.

5. Originally Posted by Buchan
Sorry for the confusion. One cable run to a junction box, each wire within the cable then connected to it's correct colour on the next cable run (underground) to the next junction box (again each coloured wired connected up to its colour) that then runs into the house and into the modem.
Oh right ok. It's going to be either a dodgy connection, dodgy junctions, dodgy cable or crosstalk/interference from mains cables etc running alongside. 30m is well within spec.

Do you know anyone who can make you up a length of cable you can just plug in to bypass the existing cable run for the purposes of elimination? You'll then know straight away if the problem is with the existing cabling or your hardware/switch/ethernet card etc.

6. Originally Posted by Legolas
Buchan,

hopefully we'll chat later this week and get it sorted. Data transmission is different to voice or electrical transmission as it relies on more than just an electrically conductive circuit. There are 8 strands of wire all twisted togeher in a Cat 5 cable and if you untwisted them all, they'd all be different lengths, the purpose being that the kit that sends the signal down the wire sends the signals at different speeds down each strand so that they all get to the other end in the correct order depending on the length of the strand it is sent down. As soon as you put something like a junction in the way, let alone three of them then you're asking for trouble.

Anyway, I'm sure we can get it sorted.
I wouldn't worry too much about the junctions, on a run of thatlength the delay skew ( difference in time between signal on each pair arriving at the destination) would be minimal and even if it was a long run with a lot of skew you would still keep a network connection though at a lower speed.
Ethernet will fall back incrementally from the fastest speed of that kit to slower speeds to maintain a connection.

I would be looking less at the cable and more at the connections at either end.
I have had video streaming working perfectly over a 25+ metre piece of cw1308(BT phone cable)wired up to RJ45 sockets(network plug/sockets) so cat 5 even with joins will work a treat.

The fact that you get a network connection then drop it is typical of a dodgy/damaged connection in the socket/plug. I would change these as it is an easy task compared to ripping out the cable and will likely fix the temperamental connection.

If you need some outlets pm me and I'll send some in the post.
Got a/shed full of the stuff

7. Originally Posted by csl
crosstalk/interference from mains cables etc running alongside.
CSL, it'll not be crosstalk from an external source as that isn't cross talk, and you can run an unshielded cat5/cat6/cat6a cable parallel to single phase mains without that being a problem too - within the standards to boot. It's the joints I'll wager!!!

8. Originally Posted by Legolas
CSL, it'll not be crosstalk from an external source as that isn't cross talk, and you can run an unshielded cat5/cat6/cat6a cable parallel to single phase mains without that being a problem too - within the standards to boot. It's the joints I'll wager!!!
Fair point, but I did mean crosstalk OR interference.

Also, I've seen cables with broken pairs still working. Ethernet can negotiate a connection without all the pairs having continuity... The symptoms described could also be down to duplex mismatch on the ethernet cards.

If it was me personally I'd quickly make up a bypass cable as I said, quickly eliminate everything else and then concentrate on the cable run!

9. Originally Posted by Legolas
CSL, it'll not be crosstalk from an external source as that isn't cross talk, and you can run an unshielded cat5/cat6/cat6a cable parallel to single phase mains without that being a problem too - within the standards to boot. It's the joints I'll wager!!!
If the connectioons have caused the installer to remove the twists then the crosstalk will increase, if the installer has split the pairs (ie, wired ONE wire of the orange pairs onto a different colour) then the crosstalk will go through the roof. Keeping the twisted pairs as pairs is crucial.

Still recon its the end connections though, seen it before a good few times

What tester has been used? Don't forget that the test is only at one point in time, a network needs the connection to be solid all the time.

10. As long as you have 2 pairs wired on pins3&6 (1 pair) and 1&2 (another pair) you will get up to100 Mbits/sec.you only need4 pairs for gigabit, 1000mbits

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