TECH

Today has been frustrating, but there was a light at the end of it all. I was working from home today remotely on one of the servers in the garage when it lost connection. At first I thought the server had gone down as I couldn’t ping it, as I had been having a few power problems I had a quick look at the fuses to see if they had tripped but everything was ok.. I then tried to talk to the some of the other machines in there and couldn’t... ok.. strange.. I checked the switch in my office and it all looked ok although the light for the garage connection was off. Went into the garage.. servers were powered up just no connection... back into the house.. scratched my head a bit.. back outside.. put my head round the back of the garage.. now.. I have a very small.. about 20 cm gap between the back of my garage and my fence.. in there has been some brambles because its always been hard to get too and on the other side was always wasteland.. except they are now building some houses on it.. which is what I put my power problems down too.. anyway... as I poked my head round the gap I saw another face looking back at me.. hello there... I was greeted .. in an Irish accent.. I was just coming to see you... I think I may have cut through one of your wires......................

Whilst cutting down the brambles on my side he had gone thought the network cable... now.. fair play to him the cable was exactly out of the way.. as it was never very accessible round there due to the brambles and the tight space. He gave his sparky a shout and they came round in about an hour... had a chat and went off to get some CAT 5E cable. They put a new cable in for me and then borrowed my crimper to put some ends on copying what I had done before....

This took most of the afternoon and was a little annoying but these things happen.. what I was concerned about was the hassle I had with this cable in the first place... and not just this cable but another cable I had done that connects the ground and first floors of my house.. in that over a certain length I had never been able to get 100mb. The original cable that went into the garage I had to cut back and cut back until I finally got 100mb out of it.. 10mb was always ok but just couldn’t get 100mb. I had tried different types of ends, different quality cables, different switches and always I got about 30M out of it before 100mb just refused to work. Once they had put the new cable in I tested it with a LAN tester and it showed that it was wired correctly so I plugged my laptop into one end of it.. no connection.. forced it to 10mb.. connected fine and could see the servers in the garage...here we go again i thought.... I thought.. maybe its the cheap home switches I got so I set off to buy a decent one and on route made a few calls and found that other people had set up runs of 100metres with 100mb with cheap kit and little issues.... so what was I doing wrong...

Got home with a 1gb switch, had been wanting one of those anyway, and plugged that in but same result. After a trawl around the net I came across the solution to this rather long story. I had wired the cable up incorrectly. Now... I knew there was a standard way of wiring up Ethernet cable but I had thought it was just a standard, first few cables i ever did i followed it then forgot what it was and just made something up keeping both ends the same and it worked and have been doing that ever since.... and this apparently is what I have been doing wrong. The standards exist due to something about the direction that the energy flows through the twisted pairs and deviation from the standards can lead to cross talk which can lead to signal drop out.... You can get away with it on short runs but not on long runs... a quick snip of the ends.. and two new ends later I was running at 100mb between my nice new shiny 1gb office switch and the 100mb switch in the garage.

So.. moral of the story.. if you are making up RJ45 cables.. follow the standards.. don’t make up your own.

I used http://www.ablecables.com.au/568avb.htm as my reference