10BASE2

10BASE2

The 10BASE2 cabling topology (Thinnet) generally uses the on-board transceiver of the network interface card to translate the signals to and from the rest of the network. Thinnet cabling, described in Chapter 3, uses BNC T-connectors that directly attach to the network adapter. Each end of the cable should have a terminator, and you must use a grounded terminator on one end.

The main advantage of using 10BASE2 in your network is cost. When any given cable segment on the network doesn’t have to be run further than 185 meters (607 feet), 10BASE2 is often the cheapest network cabling option.

10BASE2 is also relatively simple to connect. Each network node connects directly to the network cable by using a T-connector attached to the network adapter. For a successful installation, you must adhere to several rules in 10BASE2 Ethernet environments, including the following:

The minimum cable distance between clients must be 0.5 meters (1.5 feet).
Pig tails, also known as drop cables, from T-connectors shouldn’t be used to connect to the BNC connector on the network adapter. The T-connector must be connected directly to the network adapter.
You may not exceed the maximum network segment limitation of 185 meters (607 feet).
The entire network cabling scheme cannot exceed 925 meters (3,035 feet).
The maximum number of nodes per network segment is 30 (this includes clients and repeaters).
A 50-ohm terminator must be used on each end of the bus with only one of the terminators having either a grounding strap or a grounding wire that attaches it to the screw holding an electrical outlet cover in place.
You may not have more than five segments on a network. These segments may be connected with a maximum of four repeaters, and only three of the five segments may have network nodes.

You should be able to translate cable segment lengths from feet to meters or from meters to feet. A meter is equivalent to 39.37 inches or 3.28 feet.

Figure 4.9 shows two network segments using 10BASE2 cabling. For more on 10BASE2’s Thinnet cabling, see Chapter 3.