1. CAT3网线(10Mbps)

图1 CAT3网线

2. CAT4网线已淘汰

3. CAT5 网线(100MHz,100Mbps)

Cat5 Ethernet cable introduced the 10/100 Mbps speed to the Ethernet, which means that the cables can support either 10 Mbps or 100 Mbps speeds. A 100 Mbps speed is also known as Fast Ethernet, and Cat5 cables were the first Fast Ethernet-capable cables to be introduced. Cat5 Ethernet cable can also be used for telephone signals and video, in addition to Ethernet data.

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图 2 CAT5网线

4. CAT5E网线 (100MHz,1000Mbps)

Cat5e Ethernet cable is an enhanced version of Cat5 cable to handle a maximum bandwidth of 100 MHz. Cat5e Ethernet cable is optimized to reduce crosstalk, or the unwanted transmission of signals between data channels. Although both Cat5 and Cat5e Ethernet cable types contain four twisted pairs of wires, Cat5 only utilizes two of these pairs for Fast Ethernet, while Cat5e uses all four, enabling Gigabit Ethernet speeds. Cat5e cables are backward-compatible with Cat5 cables, and have completely replaced Cat5 cables in new installations

图 3 CAT5和CAT5E的外观区别

图 4 CAT5和CAT5E的性能区别

CAT5E比CAT5有更好的抗串扰能力。
CAT5更便宜。
最大距离都是100m。

5. CAT6网线 (250MHz, 1000Mbps)

Cat6 Ethernet cable is certified to handle Gigabit Ethernet with a bandwidth of up to 250 MHz. It has better insulation (绝缘) and thinner wires, providing a higher signal-to-noise ratio. Cat6 Ethernet cables are better suited for environments in which there may be higher electromagnetic interference. Cat6 Ethernet cables can be available in both UTP and STP forms, and they are backward-compatible with both Cat5 and and Cat5e cables

图 5 CAT5E、CAT6和CAT6A的区别

图 6 UTP类型的CAT6网线

图 7 STP类型的CAT6网线

图 8 SFTP(双屏蔽)类型的CAT6网线

6. CAT6A 网线(500MHz,10Gbps)

Cat6a Ethernet cable improves upon the basic Cat6 Ethernet cable by allowing 10 Gbps (10,000 Mbps) data transmission rates and effectively doubling the maximum bandwidth to 500 MHz. Category 6a cables are usually available in STP form, therefore they must have specialized connectors to ground the cables.

图 9 STP类型的CAT6A网线

图 10 UTP类型的CAT6A网线

7. CAT7网线 (600MHz, 1Gbps)

Cat7 Ethernet cable is a fully shielded cable that supports speeds of up to 10,000 Mbps and bandwidths of up to 600 MHz. Cat7 cables consist of a screened, shielded twisted pair (SSTP) of wires, and the layers of insulation and shielding contained within them are even more extensive than that of Cat6 cables.

图 11 CAT7网线

8. CAT8网线 (2GHz, 40Gbps)

The newly upgraded Cat8 Ethernet cable supports up to 2000MHz and speeds up to 40Gbps over 20 meters. It is fully backward compatible with all the previous categories. With inner aluminum foil (铝箔) wrapped around pairs and outer CCAM braid shielding, the Cat8 Ethernet cable can prevent from electromagnetic and radio frequency interference very well.