1. Network Topologies & Standards
Vivian Arzola

2. Overview Preliminary Terms Hardware Basics Topologies
Channel Access Methods
Standards

3. Preliminary Terms Node – interconnected devices in a computer network
e.g. terminals, computers, printers, scanners, servers, repeaters, routers, etc.
Link – Physical medium connecting two nodes
cable
wireless
Packet – small block of data transmitted at one time
header
data
trailer

4. Hardware Basics Wireless Transmission Media: Radio Infrared Microwave
Lightwave (laser)

5. Hardware Basics… Copper cables Coaxial (thick/thin)
Twisted Pair (STP/UTP)

6. Hardware Basics…
Coaxial cable

7. Hardware Basics…
Twisted Pair

8. Hardware Basics…
Fiber Optic Cable
Single Mode
Multimode

9. Hardware Basics…
Multimode Fiber Optic Cable

10. Topologies Point-to-Point Multipoint (Broadcast)
dedicated physical connections
impractical for LAN’s
used for long-distance networks

11. Topologies…
Tree Topology (point-to-point)

12. Topologies…
Tree Topology (point-to-point)

13. Topologies… Point-to-Point Multipoint (Broadcast)
dedicated physical connections
impractical for LAN’s
used for long-distance networks
shared communication channel
requires coordinating use (delays)
reduces cost

14. Topologies…
Bus Topology

15. Topologies…
Ring Topology

16. Topologies…
Star Topology

17. Channel Access Methods… (preventing collisions!)
Carrier Sense Multiple Access (CSMA)
checks for electrical activity before transmission
Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
supports collision recovery
binary exponential backoff

18. Channel Access Methods… (preventing collisions!)
Polling
delays
single point of failure
no monopolization
Token-Passing
zero collisions
equal access
great performance on high traffic networks

19. Channel Access Methods… (preventing collisions!)
Demand Priority
can assign priorities
costly
single point of failure

20. Standards

21. Standards…

22. Standards…

23. Standards…

24. Questions?