02-03-2010, 08:41 AM
03-18-2010, 04:01 AM
The network layer is concerned with controlling the operation of the subnet. A key design issue is determining how packets are routed from source to destination. Routes could be based on static tables that are "wired into" the network and rarely changed. They could also be determined at the start of each conversation,Finally, they could be highly dynamic, being determined anew for each packet, to reflect the current network load.If too many packets are present in the subnet at the same time, they will get in each other's way, forming bottlenecks. The control of such congestion also belongs to the network layer.