1. Computer Networking (Appendix C) Objectives
Understand networking fundamentals
Understand network services and transmission media
Understand network software and hardware

2. Networking Fundamentals
Network consists of:
Servers – provides services
Clients – requests services
Peers – both requests and provides services
Types of networks
Server-centric networks
Peer-to-peer networks

4. Networking Fundamentals
Network Services
File services
Print services
Message services
Applications services

5. Networking Fundamentals
Network Operating System (NOS)
Two parts:
System software that runs on the server
Client software on each workstation
Examples
Banyan Vines
Novell NetWare
Microsoft LAN Manager
LANtastic

6. Networking Fundamentals
Transmission Media
The pathway to send data and information between two or more entities on a network
Bandwidth: transmission capacity
Attenuation: weakening of a signal over distance
EMI: electromagnetic interference

7. Networking Fundamentals
Cable Media
Twisted pair cable
Coaxial cable (“coax”)
Fiber-optic cable

11. Networking Fundamentals
Wireless Media
Infrared line of sight
High-frequency radio
Pager – one way wireless
Cellular phone – two way wireless
Wireless LANs
Microwave
Terrestrial
Satellite

12. Network Software and Hardware
Media access control
Rules that govern how a workstation gains access to the network
Distributed access control
Token passing
Random access control
“Listens” for network traffic

13. Network Software and Hardware
Network topologies
Star network
Ring network
Bus network

15. A star network topology
Use: This topology is useful for applications where processing must be centralized and some can be performed locally.
Advantages:
Easy to lay out and modify.
It is easy to diagnose problems at individual workstations.
Problems:
Costly, it requires the largest amount if cabling.
Since all communication pass through the central computer, the communications in the network will stop if the host/hub computer stops functioning.

17. A ring network topology
Use: This topology is useful in LANs.
Advantages:
It does not rely on central host.
The connecting wire, cable, or optical fiber forms a closed loop. Data are passed along the ring from one computer to another and always flow in one direction. The message is regenerated and passed to the next computer if it is not for the previous computer. This regeneration process enables ring networks to cover much larger distances than star or bus networks.
Disadvantages:
A failure of any node on the ring network can cause complete network failure.
It is difficult to modify and reconfigure the network.

19. A bus network topology Use: This topology is useful in LANs.
Advantages:
It does not rely on central host.
This network can still function if one of the computers malfunctions.
Other advantages: easy to wire, quick response, less expensive.
Disadvantages:
The main disadvantage is bad connection to the cable can bring down the entire network. Another problem: collision occurs when 2 nodes send messages simultaneously.

20. Network Software and Hardware
Protocols: Set of rules ( format of transmitting data, error checking method, data compression technique)
OSI model – open systems interconnection
Ethernet
TCP/IP

21. OSI RM

22. OSI RM

23. Network Software and Hardware
Connectivity hardware
Transmission Media Connectors: T-connector for coax cable and RJ-45 connectors for twisted pair
Network interface card (NIC)
Modems
Repeaters
Hubs
Bridges
Multiplexers
Routers
Brouters
Channel service units (CSU): buffer between a LAN and a WAN
Gateway