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Outlines Received due 12 October (live) By 19 October (DL)

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Outlines Received due 12 October (live) By 19 October (DL)

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  1. ECEN5553 Telecom SystemsDr. George Scheets Week #5Read [8] Internet QoS: Pieces of the Puzzle"[9a] "Technology and Architecture to Enable the Explosive Growth of the Internet"[9b] "5 Major Changes Facing the Internet in 2012"[10] "Power Consumption and Energy Efficiency in the Internet" Exam #1 (26 September - Lecture 16) DL no later than 3 OctoberOutline (12 October, Lecture 22) DL no later than 19 October

  2. OutlinesReceiveddue 12 October (live)By 19 October (DL) 20 %

  3. Exam #1 (90 points) • Wednesday 26 September (Live)Async Distant Learners, no later than 3 October • Work 3 of 4 pages • Closed Book & Notes • Calculators & phones are NOT allowed...Set up numerical problem for full credit • Equations are provided (on 5th page) • Approximately 40% of upcoming exam will be lifted from the Fall 2011 Exam #1 • Anything in the notes, on Power Point, or in reading assignments is fair game

  4. On Short Answer or Essay Questions • Answer the Question! • Memory Dump in the space provided • Knowledgeable individual can write more • Grader will look for "Power Point bullets" • Same remarks as instructor's typically not required • To get "A" or "B", instructor needs to walk away with impression you could've said more • Got space? Anything else pertinent to add? • It is NOT necessary to write small or fill up allotted space to get a good score!

  5. Wireshark Packet Capture

  6. ISO OSI Seven Layer Model MSS = 1460 B = Size of Layer 6 & 7 info per packet • Layer 7 Application • Layer 6 Presentation Windows API • Layer 5 Session Windows TCP • Layer 4 Transport Windows TCP • Layer 3 Network Windows IP • Layer 2 Data Link PC NIC • Layer 1 Physical PC NIC Ethernet Payload = ? 1500 B

  7. TCP Window Size (Layer 4) Effects End-to-End Throughput • Suppose • Window Size (set by PC) = 64 KB • Microsoft Windows XP (Actually = 64 * 1,024 - 1) • Maximum Segment Size = 1 KB • Frame size transmitted = MSS + Layer 2-6 overhead • Server can send < 64 unACK'd packets PC Server 3,000 Km

  8. Throughput on 45 Mbps Line PC Server #3 #2 #1 3,000 Km, 45 Mbps line • NPD = Prop Delay / Packet inject time • Prop Delay = distance / EM energy speed = 3,000,000 m / 250,000,000 m/sec = 0.012 seconds • Packet inject time = 8,376 bits / 45 Mbits/sec = 186.1 μseconds (PPP, IPv4, TCP) • NPD = 0.012 / 0.0001861 = 64.47 • 64.47 average sized packets will fit back-to-back on this line

  9. Throughput on 45 Mbps Line PC Server Packets 1 - 64 • At this instant in time, the Server... • Has transmitted 64 packets w/o ACK. • Has hit window limit. Halts. 3,000 Km, 45 Mbps line

  10. Throughput on 45 Mbps Line PC Server Packets 2 - 64 #1 1 ACK • At this instant in time, • The PC has processed 1st packet & sent an ACK • The Server is still halted, waiting for ACK #1. • When ACK #1 arrives at the server... • Can then transmit one additional packet. • Other ACK’s arrive fast enough to allow back-to-back transmission of next group of 64 packets 3,000 Km, 45 Mbps line

  11. Can Estimate Throughput with a Time Line to = 0 t1 t2 t3 time • to: Leading edge of 1st packet injected • t1: Trailing edge of 64th packet injected • t1 = (64*1047B)(8b/B)/(45 Mb/sec) = 11.91 msec • t2: Leading edge of 1st packet hits far side • 12 msec (propagation delay) • If ACK injected right away... • t3: ...ACK arrives at server at t = 24 msec • Process Repeats...

  12. Can Estimate Throughput with a Time Line to = 0 11.38 12.00 24.00 time (msec) • This system can transmit • 64(1,047) B = 67,008 B = 536,064 bits • Every 24 msec (one round trip time) • Estimated throughput = 536,064/0.024 = 22.34 Mbps • Actual throughput a bit lower • 1st ACK not transmitted until packet #1 fully received... • ... and processed by PC • 65th packet not transmitted until ACK #1 fully received... • ... and processed by Server

  13. Can Estimate Throughput with a Time Line to = 0 11.38 12.00 24.00 time (msec) • Need to be able to fill the pipe for 1 RTT • 24 msec in our example • 45 Mbps * .024 sec = 1.08 M b = 135,000 B = 135,000/1,047 = 128.9 packets • Window Size needs to be = 128.9 segments*1,000 bytes/segment • Actually would need another packet or two to cover source & sink processing

  14. UDP Header (8 Bytes) 4 Bytes Source Port Destination Port Checksum For interactive real-time traffic, usually used with Real Time Transport Protocol (12 bytes).

  15. Virtual Circuits • Routing decisions made once when circuit is set up • Concerned switches have internal Look-Up tables updated • All packets part of info transfer follow the same path • Allows option of setting aside switch resources (buffer space, bandwidth) for specific traffic flows • MPLS, Frame Relay, ATM, & Carrier Ethernet use VC’s

  16. Datagrams • IP uses Datagrams • Routing Tables updated independently of individual traffic flows • Routers continuously talking with each other • Packets may follow different paths • Routers get no advance warning of specific packet flows.

  17. IP is Connectionless 20 20 up to 1,460 IP TCP Data + Padding I/O decisions based on IP address & look-up table. Tables updated independent of traffic, hence path thru network may suddenly change. TCP is connection oriented.

  18. TCP, UDP, and IP • 20 year old Protocols Designed for dataOne Priority & “Best Effort” servicesNo QoS GuaranteesAvailable bandwidth depends on other users • TCP (Layer 4 & 5) provides reliable transfer • UDP (Layer 4 & 5) unreliable transfer • IP at Layer 3 • Arbitrary Protocols at Layers 1 & 2

  19. InternetTraffic2008 - 2009 Comparison source: http://www.sandvine.coms

  20. 2011 Internet Traffic Profile Source: http://www.sandvine.com/downloads/documents/ 2011 Global Internet Phenomena Report.pdf

  21. 2011 Internet Traffic Profile Source: http://www.sandvine.com/downloads/documents/ 2011 Global Internet Phenomena Report.pdf

  22. Internet Traffic Growth source: "The Road to 100G Deployment", IEEE Communications Magazine, March 2010

  23. VoIP • PC to PC • Internet Phone to Internet Phone Commodity Internet

  24. VoIP • PC to Wired Phone • Internet Phone to Wired Phone Gateway Commodity Internet Phone System

  25. VoIP (Wired Phone-to-Wired Phone) • Carrier prioritizes VoIP traffic (DiffServ) • Paths nailed down (MPLS) • Gateways control # of voice calls • Good Quality Possible with this configuration Gateway Gateway Phone System Phone System "QoS Enabled" Internet

  26. Traditional Videoconferencing 384 Kbps fixed rate output(video + audio) Camera Dedicated BandwidthNetwork: Circuit Switched TDM 6 Bytes @ 8000 times/sec *State Owned Fiber *ISDN Codec Audio Video Codec

  27. 2002 Non-Traditional Videoconferencing 384 Kbps fixed rate output(video + audio) Now > 784 Kbps Packet Switched StatMuxed Prioritized *State Owned Fiber This is technique being used in this class for video to & from Tulsa & Stillwater. Camera Codec Audio Video Codec

  28. Internet Video Streaming The Internet Quality of Received Stream depends on: (1) Size of your pipe. (2) Internet congestion. (3) Server congestion. Disk Drive PC

  29. Internet Video Streaming Disk Drive Stillwater Video Server generates packets. Fairly steady generation if server not swamped. Rate depends on pipe size.

  30. Internet Video Streaming Internet Disk Drive Video Server Packets exit at an irregular rate. Random delays. Non-Dedicated Bandwidth(Packet Switched, Stat Muxing)

  31. ISP Routes can be Roundabout Launched 30 January 2007, 2 miles from OSU campus • 1 Dr. Scheets' home router • 6 SBC routers • adsl-70-233-191-254.dsl.okcyok.sbcglobal.net • ex2-p11-0.eqchil.sbcglobal.net • 7 Level3 routers • Te-3-2.Chicago1.Level3.net • kscymo2wcx010-pos9-0-oc48.wcg.net • tulsok6wcx2-pos11-0-oc48.wcg.net • 5 ONENET routers • at least 1 in Oklahoma City • 3 Oklahoma State routers Using DiffServe, End-to-End performance on this 22 router path ...

  32. ISP Routes can be Roundabout Launched 5 September 2008, 2 miles from OSU campus • 1 Scheets' home router • 4 SBC routers • adsl-70-233-191-254.dsl.okcyok.sbcglobal.net • bb1-g1-0-2.rcfril.sbcglobal.net • 1 Equinix router • 1 Transitrail router • onenet.chcgil01.transitrail.net • 3 ONENET routers • at least 1 in Oklahoma City • 4 Oklahoma State routers • rtt = 55 msec ...may be worse than End-to-End performance on this 14 router path when not using DiffServ.

  33. LAN LAN Internet Service Provider Network PC Trunks Leased Line Router Corporate sites using Internet as WAN. Can pay ISP extra $$ → Traffic between sites gets preferential treatment. PC

  34. Interactive VOICE & VIDEO over the commodity INTERNET(Best Effort, No Priorities) • Is not ready for Prime Time • Delay & Quality problems difficult to solve under the current system... • ...although throwing Bandwidth at the problem will alleviate • Has a place for the user whose main concern is $$$$ or convenience

  35. LAN LAN Internet Service Provider Network PC Trunks Leased Line Router Routers operate at Layers 1-3. PC’s operate at Layers 1-7. Routers do not monitor opening of TCP Logical Connections. RSVP would change this. PC

  36. Multi-Protocol Label Switching • Enables Virtual Circuits • End-to-End Paths nailed down • Traffic Engineering Easier • Resource Reservation Easier • Seeing fairly widespread ISP deployment

  37. Internet QoS • Most every ISP is installing or testing one or more of following... • DiffServ • MPLS • Resource Reservation capability • Pricing structure to reflect different QoS ... but they are not yet widely deployed. • As a result, currently the Commodity Internet remains mostly • Best Effort, FIFO Routing

  38. Thinking of moving large amountsof high quality, time sensitivetraffic over the Commodity Internet? Check back in 2-3 years when... • Priorities Enabled (IPv6 and/or DiffServ) • Resources Guaranteed (Resource Reservation Protocol (RSVP) or equivalent is deployed) • Flat rate pricing is gone

  39. The Internet Is... • A superb information source • Sometimes difficult to separate wheat from chaff • IEEE Communications or Proceedings • Peer Reviewed • IEEE Spectrum • Reviewed by editor • Jane Doe's Web site • Reviewed by Jane Doe • A good marketing tool

  40. The Internet Is... a Security Nightmare • Any-to-Any connectivity is both strength and weakness • Tracert yields Router IP Addresses • Could Telnet or HTTP to many. Password? • Espionage • Read “The Cuckoo’s Egg” by Cliff Stoll • Former #1 on New York Times Best Seller • Recommended by Dr. Scheets’ Mom

  41. The Internet Is... a Security Nightmare • Bad things have been out there for years • Viruses, Worms, Trojans, Denial of Service, etc. • November 2, 1988 Internet Worm • Network shut down for 2-3 days • Took advantage of • Unix buffer overflow problems • Poor password choices • 2009-2010 Stuxnet Worm • State sponsored? • Seemed to target Iran's nuclear bomb program

  42. The Internet Is... a Security Nightmare • TCOM5233Applied Information Systems Security • Prerequisities: TCOM5123 Upper Layers • “Remember, when you connect with another computer, you're connecting to every computer that computer has connected to.” • Dennis Miller, Saturday Night Live

  43. Pros of Using the Internet • Any-to-Any Connectivity • It’s Inexpensive (save $$$$) • Tons of valuable information available • Excellent marketing/sales tool

  44. Cons of Using the Commodity Internet • Any-to-Any Connectivity puts all attached machines at risk • Slightly higher risk of Theft of Traffic • Tons of Worthless Information Available • No QoS guarantees or Guaranteed BandwidthMay have trouble rapidly moving large filesMay have trouble reliably moving time sensitive traffic WARNING: SECURITY HAZARD!

  45. 802.3 Ethernet Packet Format Bytes: 7 1 6 6 2 MAC Destination Address MAC Source Address 40 20 6-1440 4 Data + Padding IPv6 TCP CRC

  46. Connectionless vs. Connection Oriented • Connectionless* Packet delivery may be out of order * Packet delivery NOT guaranteed* Packets may be mangled* End User’s responsibility to fix any problems • Connection Oriented* Packet delivery in order* Packet delivery usually guaranteed

  47. IP is Connectionless 20 20 up to 1,460 IP TCP Data + Padding I/O decisions based on IP address & look-up table. Tables updated independent of traffic.

  48. Wide Area Connectivity Options • Leased Line Network • Switches are byte aware • Circuit is assigned trunk BW via TDM • BW required is based on peak input rates • Route through system determined in advance. • Pricing function of distance & peak rate • Most expensive connectivity option • Highest quality connectivity option

  49. Leased Line Usage Revenues still around$34 Billion in 2009 Drop in Corporate Increase in wireless backhaul Figure Source: Insight ResearchOctober 2004Network World Article

  50. Switched Ethernet LAN's Edge Router PC Leased Lines Switched Hub PC 100, 1,000 Mbps PC 10/100 Mbps PC Switched Hub PC Switched Hub PC PC

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