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

OSI

The layer boundaries should be chosen tomaximize the information flow across the interfaces

It prevents changes in one layer from affecting the other layers, so that they can develop more quickly.

Which layer of the OSI model provides services to enable user interactions with applications, such as email or web browsing?

Provides an error-free communication link