In order to realize the transmission of real-time data over IP networks, quality of service parameters for multimedia applications have been developed. Integrated Services(IntServ) and Differentiated Services( DiffServ) have been created on the basis of Quality of Service ( QoS) at a graduated level.
IntServ is designed to transmit real-time applications more efficiently and with maximum possible performance. To achieve this, the IntServ model assumes that available resources must be explicitly managed, that no service guarantees can be made without resource reservation, and that end-to-end delays are limited.
According to the procedure, in IntServ, the host asks the routers on the Internet or intranets whether the resources are available for a traffic flow from the sender to the receiver. The switching systems then establish the connection with the desired quality and maintain it until the end of the transmission. The concept provides for several priority classes representing different QoS classes.
The IntServ model is described in RFC 1633.