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10BASE-T
The trend in wiring Ethernet networks is to use unshielded twisted-pair (UTP) cable. 10BASE-T, which uses UTP cable, is one of the most popular implementations for Ethernet. It is based on the IEEE 802.3 standard. 10BASE-T supports a data rate of 10 Mbps using baseband.

10BASE-T cabling is wired in a star topology. The nodes are wired to a central hub, which serves as a multiport repeater (see Figure 4.13). A 10BASE-T network functions logically as a linear bus. The hub repeats the signal to all nodes, and the nodes contend for access to the transmission medium as if they were connected along a linear bus. The cable uses RJ-45 connectors, and the network adapter card can have RJ-45 jacks built into the back of the card.

10BASE-T segments can be connected by using coaxial or fiber-optic backbone segments. Some hubs provide connectors for Thinnet and Thicknet cables (in addition to 10BASE-T UTP-type connectors).

By attaching a 10BASE-T transceiver to the AUI port of the network adapter, you can use a computer set up for Thicknet on a 10BASE-T network.

The star wiring of 10BASE-T provides several advantages, particularly in larger networks. First, the network is more reliable and easier to manage because 10BASE-T networks use a concentrator (a centralized wiring hub). These hubs are “intelligent” in that they can detect defective cable segments and route network traffic around them. This capability makes locating and repairing bad cable segments easier.

10BASE-T enables you to design and build your LAN one segment at a time, growing as your network needs to grow. This capability makes 10BASE-T more flexible than other LAN cabling options.

10BASE-T is also relatively inexpensive to use compared to other cabling options. In some cases in which a data-grade phone system already has been used in an existing building, the data-grade phone cable can be used for the LAN.


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Networks with star wiring topologies can be significantly easier to troubleshoot and repair than bus-wired networks. With a star network, a problem node can be isolated from the rest of the network by disconnecting the cable and directly connecting it to the cable hub. If the hub is considered intelligent, management software developed for that hub type, as well as the hub itself, can disconnect the suspect port.

The rules for a 10BASE-T network are as follows: