Load Shedding in Computer Networks
It is the ultimate medicine for controlling the load. A router overloaded by packets that it can’t handle just throws them away.
Load Shedding Technique:
- Random selection in which the packets are randomly selected.
- Depending on the application old packets can be thrown away or new packets can be thrown away.
- Priority can be marked in packets by the source to indicate how important the packet is. Depending on this packet may or may not be selected for throwing away.
Random Early Detection:
The basic concept of RED method is to drop packet before situation becomes hopeless. So, in this method, the situation is tackled beforehand. The router maintains an average queue length for the outgoing lines. When the average queue length exceeds a threshold the line is said to be Congested.
The router then drops the packet at random from the queue and does not report it to the source. The source will notice a lack of acknowledgement and it’ll slow down the transmission rate assuming that a lost packet generally occurs due to congestion and discard.
Variation or standard deviation in packet arrival time is called jitter. For good quality of service low jitter is expected.