Integrated services - IntServ

1. Integrated Services
By: Ms. Pradnya Saval

2. Introduction
• To provide different QoS commitments, the IETF developed the Integrated
Services Model that requires resources such as bandwidth and buffers to be
explicitly reserved for a given data flow to ensure that the application
receives its requested QoS.
• Admission Control
• Resource Reservation Protocol (RSVP)
• Routing Algorithm
• Based on QoS parameters

3. Router Model in Integrated Services IP

4. Router Model in Integrated Services IP (Cont..)
• The model requires the use of:
• Packet classifiers – to identify flows
• Packet schedulers – to handle forwarding
• Admission Control – to determine if the router has the necessary resources to accept a
flow and for QoS
• Reservation agent – using the RSVP protocol to set up a flow

5. Router Model in Integrated Services IP (Cont..)
• Flow descriptor – describe the traffic and QoS requirement of the
flow
• Filter Specification (filterspec) – provide the information required by the packet
classifier to identify the packets that belong to the flow.
• Flow Specification (flowspec)
• Traffic Specification (Tspec) – specifies the traffic behaviour of the flow
• Service Request Specification (Rspec) – specifies the QoS in terms of bandwidth,
packet delay or packet loss

6. Services provided by Integrated Services
1. Guaranteed Services
2. Controlled Load Services

7. Guaranteed Services
• Used for applications that require real-time service delivery.
• Gives quantitative service
• Designed for firm bound on the end-to-end packet delay for a flow.
• How does Guaranteed Services provide a firm delay bound?
• Using token bucket algorithm
• Each router must know the traffic characteristics of the flow and the desired
service for admission control.

8. Controlled Load Service
• Used for adaptive applications that can tolerate delay but sensitive to
traffic overload condition.
• Gives qualitative service.
• Requires less implementation complexity than the guaranteed service.