haping is Interactive Integrated services RSVP voice & video, distr. simulations Differentiated services datacom Best effort Figure 7.16 QoS methods and their main applications Quality of Service to even out peaks in the traffic. This means that shaping introduces a delay and should preferably strike the non real-time traffic. Policing looks at the agreed service level and prevents traffic above the agreed levels in cases of high load. This means that a packet loss is introduced, SO this should not strike loss-sensitive data. See Figure 7.17. 7.5.4 INTEGRATED SERVICES Resource Reservation Protocol RSVP carries and disseminates QoS information to QoS-aware network devices along the path between a sender and one or more receivers for a given flow. See Figure 7.18. Integrated services supports real-time transfer and guaranteed bandwidth for specific 'flows'. A flow is a distinguishable stream of related datagrams from a unique sender to a unique receiver that results from a single user activity and requires the same QoS. The flow/connection must then be identified and treated in the same manner through all intermediate nodes. The flow is unidirectional and it is identified by the destination IP address and the port number. 1. Traditional method: best effort Resource Performance allocation optimization Integrated Differentiated services services Figure 7.17 Best QoS is achieved with resource allocation, traffic engineering and performance optimization Quality-of-service mechanism for IP networks A per-flow resource reservation mechanism Scalability problem Most suitable for long-lasting, delay-sensitive data flows Core network B Problems crossing administrative borders Core network A Corporate LAN RSVP = Resource reservation protocol Figure 7.18 A reserved RSVP path for a specific flow Understanding Changing Telecommunications - Building a Successful Telecom Business A path and a reservation are set up through signalling, and the signaling protocol is called the resource reservation protocol (RSVP). The receiver actu