Posted by : JAKIR HUSSAIN
In this post the Standards of RJ-45 Wiring is briefly discussed.
RJ-45 Conductor data cable contain 4 pairs of wires. Each consist a solid colored wire and a stripe of the the same color. There are two wiring standard for RJ-45 Wiring: T-568A & T-568B.
Although there are 4 pairs of wires. 10base T/ 100base T Ethernet uses only 2 pairs: Orange and Green. The other two colors Blue , Brown may be used for a second ethernet line or for phone connections.
The two wiring standards are used to create a Cross-Over Cable (T-568A on one end, and T-568B on the other end), or a Straight through Cable (T-568B or T-568A on both ends).
To Create a Straight through cable, you'll have to use either T-586A or T-586B on both ends of the cable. The picture left hand side shows clip of the RJ-45 Connect Down.
To Create a Cross-Over cable, you'll wire T-568A on one end and T-568B on the other end of the cable.
The Straight through cables are used when connecting Data Terminating Equipment (DTE) to Data Communication Equipment (DCE), such as computers and routers to modem's(gateway's) or hub's(Ethernet switches). The Cross Over cable are used when connecting DTE to DTE, or DCE to DCE; such as computer to computer, computer to router, or gateway to hub connections. The DTE equipment terminates the signal, while DCE equipment do not.
Straight through cable is used to connect
- Host to Switch or Hub
- Router to Switch or Hub
- Switch to Switch
- Hub to Hub
- Host to Host
- Hub to Switch
- Router direct to Host
More on Straight through & Cross-Over connections:
The RJ-45 data cables we used to connect computers to a Ethernet switch is straight-through cables. As noted above, the RJ-45 cable uses only 2-pairs of wires: Orange (pins 1&2) and Green 3&6). Pins 4,5 (Blue )and 7,8(Brown) are NOT used straight through cable, as its name suggests, connects pins 1 to pin1, pin2 to pin2, pin3 to pin3 and pin6 to pin6.
Cross Over cables are used to connect TX+ to RX+ and TX- to RX- which connects pin 1 to pin 3, pin 2 to pin 6, pin 3 to pin 1 and pin 6 to pin 2. The unused pins are generally connected straight through in both Straight-through and Cross-Over cables.
To network two computers without a hub, a cross-over cable is also used to connect a router to a computer, or ethernet switch to another ethernet switch witch out an uplink. Most ethernet switches today provide an uplink port, which prevents a use of cross-over cable to daisy chain another ethernet switch, Straight-through cables are used to connect a computer to an ethernet switch, or a router to an ethernet switch.
Pin Number Designations
There are Pin number designation for each color for T-568A and T-568B
RJ-45 Color coded Scheme
RJ45 cables have 8 color-coded wires, and the plugs have 8 pins and conductors. Eight wires are used as 4 pairs, each representing positive& negative polarity. The most Commonly used wiring standard for 100 base T is T-568B a standard described above.Prior to EIA 568A and 568B standards, the color coded scheme was used to wire RJ-45 cables.
|Pin||Colored Scheme||T-568B (Common)||T-568A|
|1||Blue||Orange Stripe||Green Stripe|
|3||Black||Green Stripe||Orange Stripe|
|5||Green||Blue Stripe||Blue Stripe|
|7||Brown||Brown Stripe||Brown Stripe|
|8||White (or Grey)||Brown||Brown|
What are T-568A and T-568B wiring standards, how are they different?
>>> T-568A and T568B are the two wiring standards for RJ-45 connector data cable specified by TIA/EIA-568-A wiring standard document. The difference b/w the two is the position of the Orange Green wire pairs.
What is RJ stands for?
>>> RJ stands for Registered Jacks. These are used in telephone and data jack wiring registered with FCC.
RJ-11 is a 6- position, 4-conductor jack used in telephone wiring and
RJ-45 is a 8- position, 8-conductor jack used in 10base T and 100 baseT ethernet wiring.
What is UTP cable?
>>> UTP stands for Unshielded Twisted Pair, it is the cabling system with one or more pair pairs of twisted insulated copper wires contained in a single sheath. It is the most widely used cabling system in telecommunications and date communications environment today.