- all workstations connect to the same cable segment
- commonly used for implementing Ethernet at 10mbps
- the cable is terminated at each end
- wiring is normally done point to point
- a faulty cable or workstation will take the entire LAN down
- two wire, generally implemented using coaxial cable during the 1980's
The bus cable carries the transmitted message along the cable. As the message
arrives at each workstation, the workstation computer checks the destination
address contained in the message to see if it matches it's own. If the address
does not match, the workstation does nothing more.
If the workstation address matches that contained in the message, the
workstation processes the message. The message is transmitted along the cable
and is visible to all computers connected to that cable.
There are THREE common wiring implementations for bus networks
- 10Base2 (thin-net, CheaperNet) 50-ohm cable using BNC T connectors,
cards provide transceiver
- 10Base5 (ThickNet) 50-ohm cable using 15-pin AUI D-type connectors and
external transceivers
- 10BaseT (UTP) UTP cable using RJ45 connectors and a wiring centre
Physical Implementation Of A Bus Network
The above diagram shows a number of computers connected to a Bus cable, in
this case, implemented as Thin Ethernet. Each computer has a network card
installed, which directly attaches to the network bus cable via a T-Connector.
It is becoming common to use 10BaseT (UTP) for implementing Ethernet LANS.
Each workstation is wired in star fashion back to a concentrator wiring centre
(hub). The hub is a multi-port device supporting up to about 32 ports. One of
these ports is connected to a server, or the output of the hub can be connected
to other hubs.
Bus Network Topology Summary
| Advantages |
Disadvantages |
| Easy to implement |
Limits on cable length and Workstation numbers |
| Low Cost |
Difficult to isolate network faults |
| |
A cable fault affects all workstations |
| |
As the number of workstations increase, the speed of the network
slows down |
|
