CONNECTION TO PACKET SWITCHES:

 A packet switch many join to devices and to other packet switches. But the speeds are different in both parts. There are typically high-speed joins to other packet switches but lower speed joins to the devices. The technology details relay upon desired speed.

PACKET SWITCHES AS A BUILDING BLOCKS:

 Packet switches may be linked together to form WAN. WAN have not be symmetric or have regular connections. Every switch may connect to one or other switches and one or more devices as given in the figure below.

STORE AND FORWARD:

 Data delivery from one computer to another is completed through forward and store technology. In this technology packet switch saves incoming packet and also forwards that packet to another computer or switch. For this function packet switch has internal storage into which it may hold packet if outgoing connection is heavy. Packets for every connection held on queue.