Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Principles for QOS Guarantees (more) Alternative to Marking and Policing:allocate a set portion of bandwidth to each application flow;can lead to inefficient use of bandwidth if one of the flows does not use its allocation 。 PRINCIPLE 3:While providing isolation,it is desirable to use resources as efficiently as possible packet marking 1 Mbps 1 Mbps logical link H3 R1 R2 1.5 Mbps H2 5 Mbps logical link H4 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.6
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.6 Principles for QOS Guarantees (more) • Alternative to Marking and Policing: allocate a set portion of bandwidth to each application flow; can lead to inefficient use of bandwidth if one of the flows does not use its allocation • PRINCIPLE 3: While providing isolation, it is desirable to use resources as efficiently as possible
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Principles for QOS Guarantees (more) 。 Cannot support traffic beyond link capacity PRINCIPLE 4:Need a Call Admission Process;application flow declares its needs,network may block call if it cannot satisfy the needs 1Mbps 1.5 Mbps R2 H2 H4 1 Mbps 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.7
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.7 Principles for QOS Guarantees (more) • Cannot support traffic beyond link capacity • PRINCIPLE 4: Need a Call Admission Process; application flow declares its needs, network may block call if it cannot satisfy the needs
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Summary QoS for networked applications nnnn aunosa yy 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.8
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.8 Summary
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Outline Overview of QoS in IP networks Integrated Service model (IntServ) Resource Reservation Protocol (RSVP) Differentiated Services model (DiffServ) 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.9
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.9 Outline • Overview of QoS in IP networks • Integrated Service model (IntServ) • Resource Reservation Protocol (RSVP) • Differentiated Services model (DiffServ)
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Integrated Service (Intserv) The Integrated Services model(RFC1633)was introduced to guarantee a predictable behavior of the network for applications requiring QoS guarantee applications signal to the network that they require special QoS data flows among applications,with flow recording at each router SP ISP 3 ISP4 ISP 2 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.10
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.10 - The Integrated Services model (RFC1633) was introduced to guarantee a predictable behavior of the network for applications requiring QoS guarantee - applications signal to the network that they require special QoS - data flows among applications, with flow recording at each router Integrated Service (Intserv) ISP 1 ISP 2 ISP 3 ISP 4