This document discusses different methods for allowing one-to-one communication between nodes in large networks, including direct connections, central controllers, and common buses. It focuses on switching networks, which consist of interlinked switches that can create temporary connections between devices. There are three main types of switching networks: circuit switching, packet switching, and message switching. Packet switching breaks messages into small packets that contain user data and control information and are briefly stored at nodes before being passed to the next node.

2.  In large networks we need some means to
allow one-to-one communication between
any two nodes.
 In LANs this is achieved using one of three
methods:
• Direct point-to-point connection (mesh)
• Via central controller (star)
• Connection to common bus in a multipoint
configuration (bus)
• The solution is Switching Network

3.  Consists of a series of interlinked nodes
called switches.
 Switches are capable to create temporary
connections between two or more devices.

6. Namely :
 Circuit Switching
 Packet Switching
 Message Switching

7.  A circuit-switched network consists of a set
of switches connected by physical links.
 A connection between two stations is a
dedicated path made of one or more links
 each connection uses only one dedicated
channel on each link
 Each link is normally divided into n
channels by using FDM or TDM.
 The link can be permanent (leased line) or
temporary (telephone)

9.  Designed for data
 Transmitted in Small Packets
 Packets contain user data and control info
- user data may be part of larger message
- control info includes routing (
addressing info)
 Packets are received, stored briefly(buffered)
and passed onto the next node

11.  Typically, a general purpose computer
 Needs storage capacity to store the
incoming messages(long)
 Message priorities due to store-and-forward
technique
 Traffic Congestion is reduced