Network Cabling
From MissionTechWiki
Contents |
What is Network Cabling
Basically this relates to cabling issues in physically setting up the Physical Layer of a network. The basics are no different from anywhere else, but due to cost limitations, and sometimes technology access, the equipment in use can be a generation or two older than in commercial networks. So we want to gather knowledge about doing networking cost effectively here that we can't find elsewhere, or to point to information that isn't easy to find.
Office Cabling
Twisted Pair
For new installations, it is useful to standardize on Cat5 cable for both networking and phone, so you have to buy only one kind of cable. Cat5 cable allows up to 4 phone lines in one cable.
For Networking
Cat5 cable easily supports 100mbps LANs. If you think you might want gigabit LAN in the future, install Cat6 or better.
For Telephone
Fibre
Powered Ethernet
Interbuilding Cabling
A common problem that missions have is connecting a network between buildings where they only have standard telephone twisted pair cables in place, and installing Fibre is too expensive. As well as cabling, you might want to consider a wireless connection.
The issues
There are two main issues that create problems when running network cables between buildings:
- lightening/surge protection - including earth problems in many countries.
- Distance limitations of standard equipment. Ethernet maxes out at a 328ft limit (100 meters) over that CAT3. With special equipment you can push slower speeds over longer distances (10Mbit over 200-300 meters) but quality becomes a significant problem. One other distance limitation: 600 feet between access points (vaults, hand-holds, etc). You can push gigabit over multi-mode fiber to 550 meters, and over single-mode fiber to 40 kilometers.
Some solutions
- Check for cross-talk in telephone cable pairs. USe ones with low cross-talk if distance isn't a problem.
- Use 10baseT or 10base2
- Whatever you do with networking over that 100 pair bundle, be sure
to install lightning/surge suppression. See: http://www.itwlinx.com/ for some products. Be sure you have a minimum of 10 feet of wire between the suppressor and the switch (depending on the type of suppressor, that's how far the surge will travel past the suppressor before the suppressor kicks in). A combination of fuses and avalanche suppressors is often effective -- the avalanche device protects against overvoltage, the fuse against overcurrent (often caused when the avalanche device kicks in). (greg Beeley on iccm-tech)
- roll-your-own DSL (Greg Beeley)
- Use Wireless with cantenna antenna
- Purchased version http://www.cantenna.com/
- Home made version http://www.turnpoint.net/wireless/cantennahowto.html
- hookup an old 10Base2 card (seriously) using 50 Ohm cable.
It will be good to over 600 foot and is more immune to noise. You will also get a consistent 10Mbit transfer speed. (Randall Perry)
- We're using these over phone pairs successfully to connect 4 "out buildings" to our main building over unused phone pairs: http://www.corinex.com/web/docx.nsf/(w)/eng-corinex_av_phoneline_ethernet_bridge
They work solidly, run around 40-50Mbps (in my testing). Every once in a while we have to reset one, but they work quite well. About $150/ea (need 2) from smarthome.com. I'm pretty sure the furthest distance is around 500 feet or so. (Dan Perik)
- Made by TUT Systems Inc. the XL600 Repeater http://www.tutsystems.com/support/ethernetworking/xl_600ld_ether_repeat/index.cfm)
These little ( expensive at $318.00 each ) boxes use just two UTP wires to make a connection between them and can extend your network connection over the 300 ft. limit to 600 ft. You use pins 3 and 6 (same pair of wires i.e. brown/brown white) on an RJ45 connector to plug into the XL600. The two wires are punched down on your telephone board.
Then the repeaters are plugged into a hub vie a patch cable and the network is extended. So far the thing is working great and the connection is stable and as fast as the network (we are at 10mbs).