Load Shedding – A Simple Explanation
Load Shedding is applied when none of the techniques solve the congestion in the network. The main technique is that the congested router drops incoming packets. Which packet is to be dropped depends on the type of the data being transmitted and their importance.
One way is to select packets randomly and drop them. However, if the data being transmitted is a file, it is a good idea to drop new packets and if the data is for multimedia, old packets can be dropped. Keeping older packets is called wine policy and keeping new packets is called milk policy.
Sender can also indicate which packets are important and which are not, to make the decision easy. Senders can also be allowed to violate the agreement made during virtual circuit set up and it can send more data than its limits by setting them as low priority ones. This is a good technique to utilize bandwidth more in load shedding.