In this chapter, we have given an overview of the components that go towards making multimedia on the Internet feasible and flexible. We have looked at media capture and encoding, at network models for transmission, and at some of the basic ideas in the area of service models for such transmission, as well as coordination of these delivery services.
As well as sending and receiving multimedia traffic from end systems, the network must provide some minimal performance guarantees somehow or other, to give the quality required by the end user. Within this minimum, there may e variation in network performance (throughput, delay, loss and so on) which is accommodated by adaption in end systems.
As well as supporting communication, there must be mechanisms to prevent unwanted communication, and also to prevent attacks on desired communication.
At a higher level, there have to be mechanisms for humans to create, advertise and discover the existence of multimedia sessions, and to be able to find which are the relevant applications for a given session.
Finally, there are data communication tools that allow users to coordinate sessions consisting of multiple media tools running on multiple systems, to allow seemless communication which transcends traditional telephony, television and data communications.