1 / 22

Outlines Received due 13 March

Outlines Received due 13 March. 30 %. NO CLASS Week of 13-15 March (Spring Break). MID-TERM. 1 Hour 15 minute Test Work 4 of 5 pages Know the last midterm Memory Dump in the space provided Closed Book & Notes Calculators are NOT allowed ...Set up numerical problem for full credit.

lindsey
Download Presentation

Outlines Received due 13 March

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. OutlinesReceiveddue 13 March 30 %

  2. NO CLASS Week of 13-15 March(Spring Break)

  3. MID-TERM • 1 Hour 15 minute Test • Work 4 of 5 pages • Know the last midterm • Memory Dump in the space provided • Closed Book & Notes • Calculators are NOT allowed...Set up numerical problem for full credit

  4. Term Paper • Due by COB 12 April 2000 • Remember to probe further • Any statements not ‘common knowledge’ should be cited in the body of your paper • Don’t ask what I want to see, ask what you want to see

  5. Voice (Video) on LAN (WAN) • More complex system than circuit switched voice • Packet Assembler • Transmitter Buffer • Receiver Buffer • End-to-End Delays > Circuit Switch TDM • Delay Variability > Circuit Switch TDM

  6. Switched Network Carrying Capacity • Line Speed: Traffic injection speed • Efficiency: Ability to use that Line Speed • Carrying Capacity:Ability to usefully use the Line Speed • Accounts for packet overhead • Accounts for inability to fully load StatMux trunk lines & have a usable connection • Accounts for inability to fully load TDM trunk lines with random, bursty traffic

  7. Switched Network Carrying Capacity:Queue Length • 100,000,000 bps output trunk • 100,000,001 bps average input • Average Input rate > Output rate • Queue Length builds up(without bound, in theory) • Delays go to infinity, Nothing gets dropped

  8. Infinite Length Queue (Classical StatMux Theory) Probability of dropped packets Average Delay for delivered packets 0% 100% Trunk Offered Load

  9. Finite Length Queue (Real World) Probability of dropped packets Average Delay for delivered packets 0% 100% Trunk Offered Load

  10. Finite Length Queue (Real World StatMux) Probability of dropped packets Self-Similar Classical Average Delay for delivered packets 0% 100% Trunk Offered Load

  11. Packet Switch StatMux Trunking(Pure Internet Model) Time Sensitive Traffic Router SONET OC-N Bursty Data Traffic Assumptions: All Time Sensitive Traffic (mainly voice) is packetized. All traffic is Statistically Multiplexed onto the trunk BW.

  12. Cell Switched StatMux Trunking(ATM Model) Time Sensitive Traffic ATM Switch SONET OC-N Bursty Data Traffic Assumptions: CBR traffic gets near-TDM like service. Data Traffic is StatMuxed onto the remaining trunk BW.

  13. Circuit Switch TDM Trunking(Old ‘Private Line’ Network Model) Time Sensitive Traffic TDM Switch SONET OC-N Bursty Data Traffic Assumptions: All Time Sensitive Traffic (mainly voice) is Fixed Rate. Bursty Data Traffic channels (from any data source) receive dedicated trunk BW based on peak (line) rates.

  14. Hybrid TDM Trunking(Network Model for older Carriers) Time Sensitive TDM Switch PacketSwitch SONET OC-N Bursty Data Assumptions: All Time Sensitive Traffic (mainly voice) is Fixed Rate. Bursty Data Traffic is all StatMuxed onto a common fabric (such as Frame Relay). Aggregate streams are TDM cross connected onto SONET.

  15. Switched Network Carrying Capacities TST = 8 kbps Fixed Rate VoiceSONET OC-3 Trunk Hybrid Carrying Capacity Cell Switch StatMux Packet Switch StatMux Circuit Switch TDM 0% Data 100% Data 100% TST 0% TST Offered Load

  16. Switched Network Carrying Capacities8 Kbps VBR-rt VoIP over ATMSONET OC-3 Trunks Hybrid Carrying Capacity Cell Switch StatMux Packet Switch StatMux Circuit Switch TDM 0% Data 100% Data 100% TST 0% TST Offered Load

  17. Switched Network Carrying Capacities8 Kbps VBR-rt Native ATMSONET OC-3 Trunks Carrying Capacity Hybrid Packet Switch StatMux Cell Switch StatMux Circuit Switch TDM 0% Data 100% Data 100% TST 0% TST Offered Load

  18. Carrying Capacity... • Got bursty data trafficto move?A packet switched system using statistical multiplexing will allow you to service the most users given a fixed chunk of bandwidth. • Got time sensitive fixed rate traffic to move?A circuit switched system will allow you to potentially service the most customers given a fixed chunk of bandwidth.

  19. Internet Voice Capacity looks bad... or does it? • Circuit Switched TDM (POTS) somewhat locked into 64 Kbps15.6 simplex calls per Mbps deployed bandwidth • 8 Kbps G.729 compressed voice has about same quality as 64 Kbps G.711 • ATM CBR @ 8 Kbps111.2 simplex calls per Mbps deployed bandwidth

  20. Voice Quality vs. Bit Rate Quality G.711 G.729 G.728 G.726 G.723.1 8 16 32 64 Bit Rate (Kbps)

  21. Variable Rate Voice Coders • 8 Kbps G.729 using Silence Suppression • Active 40% of time at 8 Kbps • Silent 60% of time at 0 Kbps • 3.2 Kbps average rate for a simplex conversation • Up to 125 calls per Mbps deployed bandwidth for VoIP • Up to 113 calls per Mbps deployed bandwidth for VoIP over ATM • Up to 188 calls per Mbps deployed bandwidth for native VBR ATM

More Related