Chapter 7 - Network Topologies Flashcards
Topology
The geometric arrangement of the computers in a network.
Personal computer LANs
- Low cost
* Limited data rate
Back end networks
Interconnecting large systems (mainframes and large storage devices) • High data rate • High speed interface • Distributed access • Limited distance • Limited number of divices
Storage Area Network
- Separate network handling storage needs
- Detaches storage task from specific servers
- Shared storage facility across high-speed network
- Hard disks, tape libraries, CD arrays
- Improved client-server storage access
- Direct storage to storage communication for backup
High speed office networks
- Desktop image processing
* High capacity local storage
Backbone LANs
- Part of network infrastructure that connect various piece of network.
- Interconnect low speed local LANs
- Reliability
- Capacity
- Cost
Bus Network
- The ends are not connected
- All communications are carried on a common cable or bus and are available to each device on the network.
- Maintained by contention
Contention
If a line is unused, a terminal or device can transmit its message at will, but if two or more terminals initiate messages simultaneously, they must stop and transmit again at different intervals.
Pros of Bus Network
- It has a single line to which all the network needs are attached
- Smaller size network
- The bur is simple, reliable in a small network
- It requires the least amount of calbe
Cons of Bus Network
- Heavy network traffic can stand a bus network since only one computer at a time can send a message.
- If there is a problem with the cable, the entire network breaks down.
Ring Network
• A circle or point-to-point connections of computers at dispersed locations, with no central host computer.
• All of the nodes are connected in a closed loop.
• Messages travel around the ring, with each node reading those messages addressed to it.
• Repeaters joined by point-to-point links in closed loop
- Revieve data on one link and retransmit on another
- Links unidirectional
- Stations attach to repeaters
• Data in frames
- Circulates past all stations
- Destination recognizes address and copies frame
- Frame circulates back to source where it is removed
- Only one station can transmit at a time
Pros of Ring Network
• A ring network links all nodes together in a circular chain.
• They can span larger distance than other types of networks because each nodes regenerates messages as they pass through it.
• Data/message travel in only ONE direction
- no one computer can monopolize the network
- It problem better than bus network.(data transfer rate)
Cons of Ring Network
- One faulty device can create network problems for the Ring network.
- Moves/add and changes of devices can affect network
- spam
Star Network
• Used to connect one or more small computers or peripheral devices to a large host computer or CPU.
• Each station connected directly to central node
- Usually via two-point-to point links
• Central node can be broadcast
- Physical star, logical bus
Pros of Star Network
- A star network has a central controller that is responsible for managing the network.
- All message are routed through the central controller(switch) which act as a traffic police to prevent network collisions
- Easy to install and extend
- Easy to disconnect faulty devices.
- Single computer failure does not necessarily bring down the entire network. (no disruption)
