Dicuss Computer Network in Details.

Computer Network :

• Set of serial lines to attach terminals to mainframe?
• Telephone network carrying voice traffic?
• Cable network to disseminate video signals?

What Distinguishes a Computer Network?

• Generality
• Built from general-purpose programmable hardware
• Supports a wide range of applications

Applications – Consumers of Networks:

• On a simple click, several messages may be exchanged over the Internet
• In a web browser, 17 messages may be exchanged

1. up to six messages to translate the server name
2. three messages to set up a TCP connection
3. four messages to send HTTP “get” request + response
4. four messages to tear down the TCP connection

• Moreover, millions of messages are exchanged each day by Internet nodes to make their presence and services known 

Applications – the Driving Force:

1. Streaming audio and video is an emerging application

• The source generates and sends the video stream in messages across the Internet

      2. Video-on-demand: reads a preexisting movie

• One-way data transfer

     3.Videoconferencing: interactive session

• Very tight timing constraints

    4.Diversity of applications that can be built on top of the Internet hint at the complexity of the

      Internet design