Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Integrated Services Datagram Service Controlled-Load Service:Performance as good as in an unloaded datagram network.No quantitative assurances. Guaranteed Service: Firm bound on data throughput and delay. Every element along the path must provide delay bound. Is not always implementable,e.g.,Ethernet. Delay jitter or average delay not guaranteed or minimized. 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.11
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.11 Integrated Services • Datagram Service • Controlled-Load Service: Performance as good as in an unloaded datagram network. No quantitative assurances. • Guaranteed Service: - Firm bound on data throughput and delay. - Every element along the path must provide delay bound. - Is not always implementable, e.g., Ethernet. - Delay jitter or average delay not guaranteed or minimized
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Intserv Building Blocks Local Remote Admission Local Admission Control Admission Control Control Policy Enforcement Point(PEP request request request request reserve reserve reserve reserve request reply Policy Decision Point(PDP) 2 fundamentals - Resource Reservation is used to identify an application(flow)and signal if there are enough available resources for it Admission Control is used to determine if the application(flow)can get the requested resources 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.12
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.12 2 fundamentals - Resource Reservation is used to identify an application (flow) and signal if there are enough available resources for it - Admission Control is used to determine if the application (flow) can get the requested resources request request request request reserve reserve reserve reserve Local Admission Control Remote Admission Control Local Admission Control Policy Decision Point (PDP) request reply Policy Enforcement Point (PEP) Intserv Building Blocks
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Integrated -Service -Capable Router Components Routing Reservation Process Process Policy Control Admission Input Links Q(1) Shaping or rejects incoming Output Link Q2) Scheduler Packet classifier Policing packets Buffer acceptance accepts Q(N) 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.13
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.13 Integrated –Service –Capable Router Components Packet classifier Shaping Policing Buffer acceptance accepts or rejects incoming packets Scheduler Q(1) Q(2) Q(N) Routing Process Reservation Process Policy Control Admission Output Link Input Links
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Integrated-Service (IS)-Capable Router Components(cont'd) 。 Packet Scheduler:chooses the packet to be transmitted first on the output link E.g.simple priority,round robin,WFQ(Weighted Fair Queuing),... Classifier:Each incoming packet is examined to determine its class Packets in the same flow may have "preemptable"(CLP)attribute Admission Control:Determine whether a new flow can be granted without affecting existing flows Reservation Setup Protocol:Resource Reservation Protocol (RSVP) Shaper:delays flows which do not follow some rules Policing:Verifies whether the incoming flow follow some rules Queuing strategy:logical organization of the router's buffer 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.14
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.14 Integrated-Service (IS)-Capable Router Components(cont’d) • Packet Scheduler: chooses the packet to be transmitted first on the output link - E.g. simple priority, round robin, WFQ (Weighted Fair Queuing), ... • Classifier: Each incoming packet is examined to determine its class Packets in the same flow may have “preemptable” (CLP) attribute • Admission Control: Determine whether a new flow can be granted without affecting existing flows • Reservation Setup Protocol: Resource Reservation Protocol (RSVP) • Shaper: delays flows which do not follow some rules • Policing: Verifies whether the incoming flow follow some rules • Queuing strategy: logical organization of the router’s buffer
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Call Admission Session must first declare its QOS requirement and characterize the traffic it will send through the network R-spec:defines the QOS being requested T-spec:defines the traffic characteristics A signaling protocol is needed to carry the R-spec and T- spec to the routers where reservation is required;RSVP is a leading candidate for such signaling protocol 2616009:Network Traffic Engineering 7:IntServ and DiffServ Page.15
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 7: IntServ and DiffServ Page.15 Call Admission • Session must first declare its QOS requirement and characterize the traffic it will send through the network • R-spec: defines the QOS being requested • T-spec: defines the traffic characteristics • A signaling protocol is needed to carry the R-spec and Tspec to the routers where reservation is required; RSVP is a leading candidate for such signaling protocol