The most commonly used in the network is three lines and five lines, six or more. 1) the pc and network equipment connected to the hub with the cable straight cable, twisted pair, the two connections to one correspondence, this time, the hub for the mdi-x port, pc mdi mouth. 10Mbps cable twisted pair at both ends of a one-to-one correspondence can be without having to consider the sort of lines of different colors, 100m rate linked, must be produced in strict accordance with eia/tia568a or 568B wiring standard. 2) during the inter-hub cascading cascade port control switch on the mdi (both uplink) while connected to the direct line. If the hub does not have a dedicated cascade port, or inability to use the cascade port, you must use the mdi-x port level with, then we can use a crossover cable to achieve their goals, where the lines cross, that is, in cable, with one end rj-45plug a pin to the other side rj-45plug 3 feet; then two feet of one end of the rj-45plug receiving the other end of the rj-45plug 6 feet. Can be produced in the following chromatography: a-side: orange and white, orange, green, white, blue, blue, green, brown white, brown; b-side: green, white, green, orange and white, blue, blue, orange, brown white, brown. The same time, we should also know that cascaded hub between the cable length should not exceed 100 meters, the hub of the cascade should be no more than four. Cross-line less used and should be specially marked in order to avoid mistaken for straight lines, resulting in a line fault. In addition, cross-over cable can also be used in both computer directly connected 
 In lan third category of twisted-pair 10Mbps Ethernet data and voice transmission ieee802.310base-t standard. The fifth category UTP currently holds the largest lan market, the highest rate up to 100mbps, ieee802.3100base-t standard. Rj45 socket, rj45 cable you want crystal head access card or hub network devices do. Rj45 plugs and sockets are divided into three or five electrical characteristics. rj45 crystal head by pieces of metal and plastic composition of particular note is the pin number from left to right pin when the metal face of our serial number is 1-8, this serial number is very important to do the network line can not be wrong. UTP the maximum transmission distance of 100 meters. eia. / tia cabling standards set forth in the two twisted-pair line sequence 568a and 568b. Standard 568a: orange and white - 1 orange - 2, green and white - 3, Blue - 4, blue - 5, Green - 6, brown white - 7, brown - 8; standard 568b: Green and White - 1, green - 2, orange and white - 3, Blue - 4, blue - 5, orange - 6, brown white - 7, brown - 8. Application of a wiring network cabling, but both ends of the line has network rj-45plug both termination methods a, or termination methods b, are common in the network. The order of twisted pair rj45 head pin serial number - corresponds. 10m Ethernet cable 1,2,3,6-numbered wire transfer data, the 100m Ethernet network cable to wire transfer data using the 4,5,7,8 number. Why use four pairs (8 wire) twisted pair? This is mainly to accommodate more use of the premise of not transform the infrastructure, you can meet the wiring requirements of a wide range of user equipment. For example, we can at the same time with one twisted pair to voice communications. 100BASE-t4rj, the provisions of-45 twisted pair as follows: 1, 2, is used to send, 3,6 for receiving, 4,5,7,8 a two-way line. 1,2 lines must be twisted pair, 3,6 twisted-pair, 4, 5 twisted-pair, 7-8 twisted pair.