Two strand standard practice
1. Two international standard twisted pair practices on twisted pair practices have two international standards, respectively, EIA / TIA568A and EIA / TIA568B. Below we first take a look at their connection, see the figure below:
Pin sequential media direct connection signal twisted pair around the alignment order 1TX (transmission) white green 2TX- (transmission) green 3RX (reception) white orange 4 does not use blue 5 No white blue 6rx- (received) orange 7 Use white brown 8 without using brown
Pin sequential media direct connection signal twisted pair contrary to the alignment order 1TX (transmission) white orange 2TX- (transmission) orange 3RX (reception) white green 4 does not use blue 5 No white blue 6RX- (Receive) Green 7 Use white brown 8 without using brown
(EIA / TIA568A standard) (EIA / TIA568B standard)
In fact, the standard pickup EIA / TIA568A and EIA / TIA568A and EIA / TIA568B have no essential difference, just the difference in color, users need to pay attention to only when connecting two crystal heads:
1, 2 line pair is a winding; 3, 6 lines are a winding; 4, 5 lines are a winding; 7, 8 lines are a winding;
There are no definitions of 4/5, 7/8 in twisted pairs. When the line is made, it is often not paying attention to 1, 2, 3, 4 (which is connected to the 10M network in the previous year, but 10M network is relatively narrow, and the connection is good. Connecting 1, 2, 3, 4 can also visit each other). Due to the high bandwidth of 100M, it is not good to work in 1, 2, 3, 4. What is the meaning of the fault is not the same: Some computers are on the connection, the indicators on the network card and hub / switches are normal; some computers are the indicator light on the NIC bright, and the hub The / switch end indicator flashes, thereby increasing the difficulty of tap. So this error must pay high attention. Second, what is the straight cable? What is a cross cable? Typically, we will see two commonly used connection methods of twisted pairs: straight cables and cross cables. The pin sorting and applicable applications of these two cables are introduced below.
DC cable: The two ends of the crystal head are followed by 568A or 568B standard, and each set of twisted pairs corresponds to one by one. The color is the same as a set of windings. Direct cable applicable occasion: switch (or hub) UPLINK port ------------- Switch (or hub) normal port switch (or hub) Ordinary port -------------------------------- --- Computer (Terminal) NIC 2. Cross cable: One end of the crystal head follows 568A, while the other ends follow the 568B standard. That is, two crystal heads of the two crystal heads, 1, 2 of the A crystal head, 3, 6 of the A crystal head; 3, 6 of the A crystal head corresponding to the B crystal head, 1, 2. The color is the same as a set of windings. Cross-cable applicable occasion: switches (or hub) normal port ------------ Switch (or hub) normal port computer network card (terminal) ------------- Computer network card (terminal)
A-terminal crystal head arrangement order pin sequence B-terminal crystal head arrangement sequence white orange 1 white green orange 2 green white green 3 white orange blue 4 blue white blue 5 white blue green 6 orange white brown 7 white brown brown 8 brown
(Standard cross cable)
Note: If the physical distance from the two hub / switches is far, the cascading is generally used. It should be noted that the cascading length between the IEEE802.3U 100 Base-TX Class II HUB cannot exceed 5 meters, and the maximum distance of the two switches in the 100M Ethernet is 100 meters. If you have used UPLINK-level, it is no longer available next to the normal port. Third, a special twisted pair practice except for both connection methods commonly used, there is also a special twisted pair practice. This method is applied to the following: Switch (or hub) single use is normal, but once two network device levels are used, the workstation between two network devices cannot be accessed by each other, although the cable is based on Standard is made. The reason is that the PHY of the switch (or hub) is caused by the signal definition of UTP and the general situation. The following special twisted pair practice can generally solve this problem. FIG connecting the cascade is applicable: a switch (or hub) ------------ UPLINK port switch (or hub) is a normal port. Note: The same color is the same as a set of windings, a set of crossings in the two sets of windings, please see the picture below. Can you see the difference between and the distinction above? Pin sequence A-terminal crystal head arrangement order B-terminal crystal head arrangement sequence 1 white orange orange 2 orange white orange 3 white green white green 4 blue 5 white blue white blue 6 green 7 white brown white brown 8 brown brown
