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Outlines Received due 13 March 2000

Outlines Received due 13 March 2000. 18%. Homework. Review for Midterm (1 March 2000) Research Paper Readings [5] “Virtual Private Networks” [6] “Internet QoS: A Big Picture” [7] “IP Routers: New Tool for Gigabit Networking” [8] “Corporate-Class Internet? Don’t Count on It!”. Bridge.

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Outlines Received due 13 March 2000

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  1. OutlinesReceiveddue13 March 2000 18%

  2. Homework • Review for Midterm (1 March 2000) • Research Paper • Readings[5] “Virtual Private Networks”[6] “Internet QoS: A Big Picture”[7] “IP Routers: New Tool for Gigabit Networking”[8] “Corporate-Class Internet? Don’t Count on It!”

  3. Bridge • Operates at OSI Layers 1 & 2 Follows MAC • Uses MAC addresses to switch packets • May be capable of minor protocol conversions • If properly placed will improve performance • Filters unneccesary traffic • Improves Efficiency • Increases average Bandwidth to each end user • Tends to increase delay across the bridge

  4. Router • Operates at OSI Layers 1, 2, & 3 • capable of making complex routing decisions ‘peers into’ packets • Very useful on Large Networks with multiple end-to-end paths

  5. Switched Hub • ASK VENDOR!!! • May be a multi-port bridge • May route (OSI Layer 3) first packet of a flow (OSI Layer 5), bridge (OSI Layer 2) remainder

  6. The Internet • VAST collection of interconnected networks • Key Building Block:Routers running IPv4 (Layer 3) • Router link speeds range from 56 Kbps to 2.5 Gbps • Hierarchical Addressingusername@machine.institution.domain

  7. ISO OSI Seven Layer Model • Layer 7 Application Netscape • Layer 6 Presentation Win95 (API) • Layer 5 Session Win95 (TCP) • Layer 4 Transport Win95 (TCP) • Layer 3 Network Win95 (IP) • Layer 2 Data Link 3Com NIC • Layer 1 Physical 3Com NIC

  8. Internet Service Provider Backbone Trunks Leased Line Router ISP ‘Cloud’ Trunks use StatMux & Packet Switching

  9. 11Feb00 Traceroute to WWW.CISCO.COM • 3 Internal OSU routers • 2 OneNet routers border3-okc-oc3atm.onenet.net • 4 SBC routers edge1-fa0-0-0.okcyok.swbell.net • 2 Williams routers williams1-oc3-gr1.dal2.dbn.net • 7 BBNPlanet routers p1-0.lsanca1-br1.bbnplanet.net p7-3.paloalto-nbr2.bbnplanet.net\ • 2 Cisco routers

  10. 11Feb00 Traceroute to LABRATS.COM • 3 Internal OSU routers • 2 OneNet routers • OKC • 7 Williams Routers • OKC • Dallas • Tulsa • 1 Labrat Router

  11. Virtual Circuits • Routing decisions made once when circuit is set up • All packets part of info transfer follow the same path • Frame Relay & ATM use Virtual Circuits • Allows switch resources (buffer space, bandwidth) to be set aside for specific traffic flows

  12. Datagrams • Routing decisions are made “on the fly” multiple times (every time a packet hits a Router) • Packets may follow different paths • IP uses Datagrams • Routers get no ‘advance warning’ of packet flows.

  13. What works* on the Internet? Excellent • Non Real Time Data Services EMail Usenet Fax • Interactive Data Based Services File Transfer Protocol Telnet World Wide Web Good *Provided you’re not trying to sip bandwidth through a straw.

  14. What works* on the Internet? Fair • Interactive Data Based Services White Boarding Application Sharing • Non-Interactive One-Way Audio • Interactive Two-Way Audio • One way motion video • Interactive motion Video Poor *Provided you’re not trying to sip bandwidth through a straw.

  15. 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) provides unreliable transfer

  16. Interactive Telephony over the INTERNET • “... is a toy until delay and voice-quality problems are overcome”Network World, 19 August 1996

  17. Interactive VOICE & VIDEO over the INTERNET • Is not ready for Prime Time • Delay & Quality problems not likely to be solved under the current system... • ...although throwing Bandwidth at the problem will alleviate • Has a place for the user whose main concern is $$$$ or convenience

  18. Thinking of moving time sensitive traffic over the 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

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

  20. Cons of Using the 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!

  21. Worldwide ISP Revenues $8.42B ‘98 $0.19B ‘94 $1.35B ‘95 $2.40B ‘96 $5.28B ‘97 $12.10B ‘99 Source: Data Communications

  22. Internet Performance Probability of dropped packets Average Delay for delivered packets 0% 100% Trunk Offered Load

  23. Backbone Engineering • Option A)Deploy ‘best effort’ RoutersRapidly Deploy Trunk BandwidthKeep Trunks Lightly Loaded • Delays will be small • Dropped packets will be few • Quality fine for Interactive Voice/Video

  24. Backbone Engineering • Option B)Deploy more expensive QoS enabled Routers Deploy fewer, more heavily loaded Trunks Give preferential treatment to Voice/Video • Which is less expensive in the long run?

  25. 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

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