This final issue is a key issue in the development of network support for multimedia communications.
Congestion Control is a challenging problem and is concerned with providing performance guarantees for all the services supported by a network.
Congestion control is a concern for any networked system but the problem is compounded here to due the high-speed, high-bandwidth nature of modern multimedia systems.
Admission Control is a major policy employed in congestion control. The basic idea her is to limit the number of connections in a network so that performance requirements of all the admitted connections can be satisfied. Admission control is therefore a decision-making process about whether user should be admitted or not according to some conditions, such as:
Traffic enforcement and shaping strategies, scheduling and routing issues are all involved in this process.