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Request Scheduling for Differentiated QoS in Internet

Request Scheduling for Differentiated QoS in Internet. 林盈達 交大資訊科學系 ydlin@cis.nctu.edu.tw www.cis.nctu.edu.tw/~ydlin www.nbl.org.tw. B.S., NTU-CSIE, 1988 Ph.D., UCLA-CS, 1993 Professor, NCTU-CIS Founder, ITRI-NCTU Network Benchmarking Lab (NBL; www.nbl.org.tw )

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Request Scheduling for Differentiated QoS in Internet

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  1. Request Scheduling for Differentiated QoS in Internet 林盈達 交大資訊科學系 ydlin@cis.nctu.edu.tw www.cis.nctu.edu.tw/~ydlin www.nbl.org.tw HSN LAB

  2. B.S., NTU-CSIE, 1988 • Ph.D., UCLA-CS, 1993 • Professor, NCTU-CIS • Founder, ITRI-NCTU Network Benchmarking Lab (NBL; www.nbl.org.tw) • Co-Founder, L7 Networks Inc. • Areas of research interests • Design, implementation, analysis, benchmarking of Internet gateway devices • Internet security and QoS • Content networking HSN LAB

  3. Agenda • From D(evelopment) to R(esearch) • The Wall Project • From paper review to product review • The Network Benchmarking Lab (NBL) • Request scheduling at access • Request scheduling at Web site HSN LAB

  4. All-in-One Content-aware Security & QoS Gateway Wall High Speed Network Lab. CIS NCTU HSN LAB

  5. Evolution of Wall • 7-in-1(NetBSD) • Handling the problems in TCP/IP layer • NAT, Firewall, VPN, Router, BW mgnt., IDS, URL filter • 10-in-1 (NetBSD) • Content-aware • Anti-Virus, Anti-Spam, CF/Keyword • Reducing System Overheads: New Arch./Alg. • N-in-1 (Linux) • Easy to add new modules • UPnP, APP Firewall, SSL-VPN, Wireless AP HSN LAB

  6. Live Test of Wall Private LAN C (192.168.3.*) NB_4 Switch WAN (140.113.88.*) NB_5 N-in-1 Linux 140.113.88.165 7-in-1 NetBSD 140.113.88.156 File Server NB_3 10-in-1 NetBSD 140.113.88.193 NB_1 Switch Switch DMZ(10.1.88.*) Clients Private LAN B (192.168.1.*) NB_2 Private LAN A (192.168.88.*) HSN LAB

  7. Configuring Wall: NAT HSN LAB

  8. Configuring Wall : Anti-Spam HSN LAB

  9. Awards and Tech. Transfers HSN LAB

  10. Research Tasks • N-in-1 Security and QoS Gateway • Integrate Interesting functions: L7 firewall, UPNP, Wireless AP • Port to other hardware platform: IXP 425 • Improving System Performance • 4-in-1 Proxy Arch.: Spam+ Virus+ IDS+ CF (Throughput X 2) • Fast Accurate CF: Early Decision+ Oriental Keywords (N-gram) • Request Processing Throughput X3, ¼ User latency • Accuracy of blocking adult web pages (69.7%->97.2%) • Streaming-based Mail Proxy • Content security processing on IXP • Request Scheduling for Differentiated QoS • Website gateway: Multi-Resources Req Scheduling • Access gateway: Requestized-GPS HSN LAB

  11. Conclusion and Future Work HSN LAB

  12. Specification of Wall HSN LAB

  13. LAN/DMZ WAN LAN/DMZ to WAN Outbound Traffic MAC Filter Redirect In-LAN Filter Policy Route Route Out-WAN Filter NAT IPsec VPN Bandwidth Mgt. Y Y Y FTP/POP3/SMTP/ Web/URL Filter with Many-to-One NAT sniff Alerting System Intrusion Detection Y Y Out-LAN Filter Route Bandwidth Mgt. In-WAN Filter Redirect deNAT IPsec deVPN 7-in-1 System Prototyping • 7-in-1: VPN, Firewall, NAT, Routing, Content Filtering, Intrusion Detection, Bandwidth Management WAN to DMZ/LAN Inbound Traffic HSN LAB

  14. Original Web Traffic Flow New 4-in-1 Proxy Architecture USER LAYER Packet Sniffing Squid child ps 1 child ps 2 Snort USER LAYER DansGuardian Static Link Shared Lib Snort (Detect Engine) ClamAV Web User 1 SpamAssiassian Web Server DansGuardian (IP/URL/Text check) Web User 2 KERNEL LAYER File Text User/Kernel Interaction Decompressor/ Decoder File type Recognition Webfd Original Mail Traffic Flow MIME Handler USER LAYER AMaViS child ps 1 child ps 2 child ps 1 child ps 2 Snort ClamAV Port 80 Port 25 KERNEL LAYER User/Kernel Interaction AMaVis MTA Multi-Thread TCP/IP stack SpamAssassian Network Interface MailUser 1 Mail Server Mail User 2 KERNEL LAYER Inter-Process Communication 4-in-1 Proxy Architecture HSN LAB

  15. D(n, m): Have read n% of text and scored m marks so far. C: The text should belong to category C Early Decision algorithm How to compute P(D(n,m)|C)? The computation of P(D(n,m)|C’) is defined similarly. HSN LAB

  16. Server Request Scheduler at Access Gateway Internet Access Link Edge Router Access Gateway Clients Who is the next? When to send? Concurrent Responses Controller Request Release Controller Requests Q1 C Q2 S K Qn ACC1 ACC2 Response C U High Util is necessary ACCn Request Scheduling (Fair Queuing + Window Rate-Control) HSN LAB

  17. From Paper Review to Product ReviewNetwork Benchmarking Lab ITRI-NCTU Network Benchmarking Lab www.nbl.org.tw Your Exclusive Product Reviewer Don't Ship It Unless Tested at NBL! HSN LAB

  18. NBL Overview • Founded in May 2002 • Goals • Act as a 3rd-party product reviewer • Watch product qualities • functionality, performance, conformance, interoperability • Foster interactions between academia and industry • Funding sources • Membership fees from vendors • Industrial Technology Research Institute (ITRI) • Partners • Industrial Development Bureau, Ministry of Economic Affairs (MOEA) • Computer & Communications Research Labs, Industrial Technology Research Institute (CCL, ITRI) • National Chiao Tung University (NCTU) • Connectimes Magazine, Insitute for Information Industry (III) HSN LAB

  19. Testing …. • Types of testing • Functionality • Performance • Conformance • Interoperability • Benchmarking • DUTs • Security: FW, VPN, IDP, SSL VPN, CF, AV, AS, IM, etc. • WLAN: 802.11 b/g/a/n/e interoperability, mobility, roaming, streaming • Switch/Router: bridging, routing, multicast, stacking, etc. • VoIP: voice quality, call processing, interoperability, etc. • Others: load balancer, bandwidth manager, servers, etc. HSN LAB

  20. Request Scheduling for Differentiated QoS at Access Gateway HSN LAB

  21. Motivation • Bandwidth of access link is usually the bottleneck when enterprise connects to Internet • Bandwidth management at access gateway is required • Traditional packet scheduling has three problems: • Low scalability • Scheduling behind the downlink bottleneck • Excessive concurrent transmissions HSN LAB

  22. Scheduling Requests • Most application protocols on the Internet use request-responsemodel • Recent studies use request scheduling on Web QoS • The objectives of Request Scheduler (RQS) • DIFFERENTIATED • SHARED • REDUCING CONGESTION HSN LAB

  23. Primitive Idea Class A decide release Which request and When to release the request Request Scheduler Requests Request Classifier Send Requests Class C Affect Response HSN LAB

  24. Server Client Operation Model of Downlink Management Access Link Access Gateway Edge Router Internet Class Queues (FIFO) Request Classifier Release Proportion Controller Release Time Controller Send Request Response Recorder Receive Response ReQuest Scheduler HSN LAB

  25. Simulation • RQS is implemented in HTTP/Cache class in ns2 • Questions to be answered • Differentiation and Sharing • Average Bandwidth Usage • User-perceived Latency • Reducing Congestion • Inaccurate parameters • The Impact • Compensation HSN LAB

  26. Simulation Scenario Class1 S1 (40KB) S2 (20KB) C4-1 C3-1 C2-1 C1-1 C1-2 400Kb 200ms 200Kb 400ms C2-2 RQS Gateway R Class2 128Kb 50ms C3-2 100Kb 800ms S3 (10KB) 10Mb 2ms C4-2 C1-3 C2-3 C3-3 C4-3 Class3 50Kb 2000ms S4 (5KB) HSN LAB

  27. Throughput Differentiation The quantum ratio is 4:2:1 Class3 starts to send requests at 4 min. HSN LAB

  28. User-perceived Latency Analysis Delay in Gateway The sum of Delayresp and Transmission Time Client send request Gateway get request Gateway get response Client get response Gateway send request HSN LAB

  29. Conclusions • RQS provide differentiated and sharing bandwidth between various classes, and reduce congestion (68.75% in delay between gateway and server) occurring at the access link • RQS is robust to achieve the fairness between classes even when the response size estimation is inaccurate. HSN LAB

  30. Request Scheduling for Differentiated QoS at Website Gateway HSN LAB

  31. Web Bottleneck • Decomposition of Web page download time: • Real case: (Keynote business 40 Internet performance index) [2] • Bottleneck could be at network or server • Focuses on resolving server bottleneck • Website operators can completely control their servers • Offer better throughput and latency for some users – To Provide Differentiated QoS HSN LAB

  32. Problem Statement • Given • Requests of different classes • A Web server with static pages • A gateway placed in front of the Web server • Objective – Provide differentiated QoS through HTTP requests at website gateway • Request Classification • Classification should be content-aware • Request Scheduling • Partitions server throughput proportionally according to different weights • Request sending rate should not overwhelm the server • Server Probing • URL and response size HSN LAB

  33. Architecture of the QoS Website Gateway HSN LAB

  34. Request Scheduling • Decides which request can be fetched next • Partitions server throughput proportionally • Deficit Round Robin (DRR) scheduling • Decides when to release a fetched request • Releases requests according to service rate of the server • Window control mechanism 300-200=100 700-150=550 600-300=300 600 300 100 550 700 150>100 200<=300 300<=600 150<=700 ? ? ? ? ? 350-300=50 300-250=50 350 300 50 50 250<=300 150>50 300<=350 300>50 200-200=0 100 200 0 150>0 200<=200 200>100 HSN LAB

  35. Operation Scenario of the Implementation HSN LAB

  36. Throughputunder Various Fixed-Size Web Pages • QoS-disabled case • Class 1 average: 3.9 Mbps • QoS-enabled case • Class 1 average: 8.3 Mbps +176% HSN LAB

  37. Throughput Ratiounder Various Fixed-Size Web Pages • QoS-disabled case • QoS-enabled case HSN LAB

  38. User-Perceived Latencyunder Various Fixed-Size Web Pages • QoS-disabled case • Class 1 average: 442 ms • QoS-enabled case • Class 1 average: 199 ms -69% HSN LAB

  39. Conclusion and Future Work • A request scheduling algorithm deployed at the website gateway to provide differentiated Web QoS • Transparent to clients and the server • Without modifying server kernels/daemons • Classification is content-aware • Non-work-conservative for access link; but is work-conservative for the server and the reverse direction • Server throughput can be partitioned proportionally to different classes • Results summary • Three classes gets 60% 30% 10% of server overall throughput as pre-defined QoS policies, regardless what page sizes (Accurate & Robust) • The throughput and user-perceived latency of class with the highest priority can be improved by up to 176% and 69% (Successful) • Future work • Dynamically generated pages • Server cluster HSN LAB

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