Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Unit 1 Overview----A big Picture on Traffic Control and Qos in IP networks 2616009:Network Traffic Engineering 1:Overview Page.1
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.1 Unit 1 Overview----A big Picture on Traffic Control and QoS in IP networks
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Outline An overview on Internet applications and QoS requirements Internet architecture and Protocols 。 Internet traffic control and Congestion Control Traffic policing and shaping buffer management (e.g.tail drop,AQM:RED,Blue,...) Packet scheduling (e.g.WFQ,DRR,etc.). TCP,ECN,etc. Standardized services Intserv/RSVP,DiffServ 2616009:Network Traffic Engineering 1:Overview Page.2
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.2 Outline • An overview on Internet applications and QoS requirements • Internet architecture and Protocols • Internet traffic control and Congestion Control - Traffic policing and shaping - buffer management (e.g. tail drop, AQM: RED, Blue,…) - Packet scheduling (e.g. WFQ, DRR, etc.). - TCP, ECN, etc. • Standardized services - Intserv/RSVP, DiffServ
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 A Review of Internet architecture technology Applications Messaging datagram model>no direct confirmation of final receipt email (optional confirmation now)and IM emphasis on interoperation (SMS,pagers,...)delays measured in minutes - Retrieval query (request/response) 。“client-server'” ·ftp,HTTP emphasis on fast reliable transmission delays measured in seconds Continuous media generation rate~delivery rate rendering rate audio,video,measurements,control Internet telephony Multimedia conferencing related:streaming media >slightly longer timescales for rate matching video-on-demand emphasis is on timely and low-loss delivery real-time 。 delays measured in milliseconds 2616009:Network Traffic Engineering 1:Overview Page.3
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.3 A Review of Internet architecture & technology • Applications - Messaging datagram model no direct confirmation of final receipt – email (optional confirmation now) and IM emphasis on interoperation (SMS, pagers, …) delays measured in minutes - Retrieval & query (request/response) “client-server” ftp, HTTP emphasis on fast & reliable transmission delays measured in seconds - Continuous media generation rate ~ delivery rate ~ rendering rate audio, video, measurements, control – Internet telephony – Multimedia conferencing related: streaming media slightly longer timescales for rate matching – video-on-demand emphasis is on timely and low-loss delivery real-time delays measured in milliseconds
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 New applications New bandwidth-intensive applications Reality-based networking:virtual realility (security)cameras Distributed games often require only low-bandwidth control information current game traffic VolP Computation vs.storage vs.communications communications cost has decreased less rapidly than storage costs:Networked Storage system 2616009:Network Traffic Engineering 1:Overview Page.4
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.4 New applications • New bandwidth-intensive applications - Reality-based networking: virtual realility - (security) cameras • Distributed games often require only low-bandwidth control information - current game traffic ~ VoIP • Computation vs. storage vs. communications - communications cost has decreased less rapidly than storage costs: Networked Storage system
Feng Gang National Laboratory of Communication,UESTC Aug 2017 Ver 1.4 Essential need:Quality of Service ·Quality of service? Assured bandwidth from end-to-end (e.g.8Kbps for voice), communication privacy, minimal round trip time for packet delivery,Delay jitter regularity of the data flow, etc. ·Why IP QoS2 - Application is slow!(not enough BANDWIDTH) Video broadcast occasionally stalls!(DELAy temporarily increases-JITTER) - Phone calls over IP are no better than over satellite!(too much DELAY) Phone calls have really bad voice quality!(too many phone calls- PACKET DROPPS) 2616009:Network Traffic Engineering 1:Overview Page.5
2616009: Network Traffic Engineering Feng Gang National Laboratory of Communication, UESTC Aug 2017 Ver 1.4 1: Overview Page.5 Essential need: Quality of Service • Quality of service? - Assured bandwidth from end-to-end (e.g. 8Kbps for voice), - communication privacy, - minimal round trip time for packet delivery, Delay jitter - regularity of the data flow, - etc. • Why IP QoS? - Application is slow! (not enough BANDWIDTH) - Video broadcast occasionally stalls! (DELAY temporarily increases – JITTER) - Phone calls over IP are no better than over satellite! (too much DELAY) - Phone calls have really bad voice quality! (too many phone calls – PACKET DROPPS) -