In most networks in use at the moment there will generally be a number of different services provided and used by the network and there may be multiple links to other networks. With so many services in place we can use up bandwidth very quickly. The easiest way to ensure you have enough bandwidth for all the services and users on your network is to buy fast links with low contention. This is a good theory, but the economic reality is a little bit more complex, as bandwidth can be expensive and can be a major overhead to a service. In order to combat this, we can work with the services we have and try to reduce their bandwidth usage.

Reducing bandwidth usage can initially be accomplished by using protocols that conserve bandwidth where possible; sometimes, however, we have no choice and have to go with a particular protocol dictated by an application, a vendor, or a user. This is when we can look at reducing the strain put on the network by that application. There are...