Computer Networking

• The object of networking is communication between applications on different computers
• The networking consist of Lan, Man , Wan
• Four Steps to Networking
1. Communicating across a link
2. Connecting together multiple links (internetworking)
3. Finding and routing data to nodes on internetwork
4. Matching application requirements
A. First step : Creating a link between nodes

• Types of Links
a) Point to point b) Multiples access



• Packet Transmission Modes
Unicast, Broadcast, Multicast, Anycast
• Switch network : moves bits between links ,Packet switching and Circuit switching
• Packet switching : Interleave packets from different sources
• Statistical Multiplexing Gain
1 Mbps link; users require 0.1 Mbps when transmitting; users active only 10% of the time.
• Characteristics of Packet Switching
Store and forward ; Packets are self contained units,Can use alternate paths – reordering
B. Second Step: Internet[work]
1. A collection of interconnected networks
2. Host: network endpoints (computer, PDA, light switch, …)
3. Router: node that connects networks
4. Internet vs. internet
• Challenge
1. Many differences between networks : Address formats,Performance – bandwidth/latency,
Packet size, Loss rate/pattern/handling, Routing.
2. How to translate between various network technologies
C. Third Step
1. Naming , Domain Name System, Packet Routing/Delivery, Address Resolution Protocol, Routing
D. Fourth Step: Application Demands
1. Reliability : Corruption, Lost packets
2. Flow and congestion control
3. Fragmentation
4. In-order delivery
• Problem: Network Overload
• Network Functionality Summary : Link,Multiplexing , Routing, Addressing/naming (locating peers),Reliability, Flow control, Fragmentation.
• Layering is Modular approach to network functionality
• Protokol: Module in layered structure
• E.g.: OSI Model: 7 Protocol Layers : Physical, Data link , Network ,Transport, Session, Presentation, Application
• Lecture Tropick : Traditional and Resent Tropics
• Design Considerations : determine split of functionality, Assigned Reading


Nama : Khairil Anam
NPM : 06 2009 1 05095
No abs : 22