Comprising a sequence of physical links with a dedicated logical channel

Circuit Switching depend on

Commonly used in traditional telephone networks

in Packet Switching Data sent in sequence

No need to dedicate transmission capacity along a path through the network.

Dedicated resources during a conversation : no sharing

End systems connect to Internet via access ISPs

If we have 1 Mb/s link, and each user need to be active 100Kb/s in 10% of time then How many users will be supported in Circuit switching?

at center

local ISPs

treat each other as equals

smaller (often regional) ISPs Connect to one or more tier-1

closest to end systems

Packets passed from node to node between source and destination.

TCP/IP is more

minimizes the number of layers used and makes more focus on the practical issues than the theoretical issues

ISO/OSI is more

in ISO all layers have the same Functions

OSI has ......... layers

Layers: Application, Transport, Internet, Network access