1. Outlines Received due 13 March 24 %

2. Homework n Review for Midterm on 1 March 2000 n Research Paper n Readings [11] “ATM Systems: What’s Next?” [12] “Long Distance LAN Interconnectivity”

3. MID-TERM n 1 Hour 15 minute Test n Practice LAN/MAN problems on the Web n Work 4 of 5 pages n Know the last midterm, 7 Layer Model n Memory Dump in the space provided n Calculators are NOT allowed...Set up numerical problem for full credit

4. IP over Frame Relay n 7 Application n 6 Presentation n 5 Session TCP n 4 Transport TCP n 3 Network IP n 2 Data Link Frame Relay n 1 Physical

5. Internet Service Provider Backbone If you look closely at the Router Trunks, you may find they are... Router Trunks Leased Line

6. Frame Relay is an ISP favorite... Frame Relay Virtual Circuits. FR Switch Trunks ISP Router Leased Line FR PVC

7. Frame Relay as a Corporate Backbone... n More Secure than the Internet n Can move a lot of data rapidly (if you pay for proper CIR and burst rate) n Is marginal for moving time sensitive traffic n Generally Cheaper for data than Leased Lines Fewer access lines required Backbone has higher Carrying Capacity

8. ATM n OSI Layer 2 Protocol n Uses Cell Switching 5 bytes overhead, 48 bytes traffic n Capable of hauling all types of traffic (voice, data, & video) n Works at any speed, any distance n Uses Virtual Circuits

9. ATM is a Compromise

10. Consider ATM if... n Your network is moving mixed traffic n You need sheer SPEED n You get a good deal $$$$

11. Connection Relationships n Virtual Channel: Individual Service Component. Smallest switchable unit. n Virtual Path: Group of Virtual Channels with same endpoints & QoS requirements n Backbone ATM switches: Switch VP’s n Edge ATM switches: Switch VC’s and VP’s

12. Selected ATM Parameters n PCR: Peak Cell Rate Maximum submission rate n SCR: Sustainable Cell Rate Average sustainable submission rate n MCR: Minimum Cell Rate Guaranteed minimum delivery rate n CDV: Cell Delay Variabtion Variability in cell inter-arrival times

13. ATM Classes of Service n Constant Bit Rate (CBR) Circuit Switched Emulation u Fixed rate voice or video (compressed or uncompressed) u Leased Lines u Key Parameters: PCR & CDV (small)

14. ATM Classes of Service n Variable Bit Rate - Real Time (VBR-RT) Interactive variable rate compressed voice or video u Telephony u Videoconferencing u Key Parameters: PCR, SCR, CDV (larger)

15. ATM Classes of Service n Variable Bit Rate - Non Real Time (VBR-NRT) Non-interactive variable rate compressed voice or video u Broadcast Radio u Broadcast TV u Could, and has been, used instead of ABR VC’s u Key Parameters: PCR, SCR

16. ATM Classes of Service n Available Bit Rate (ABR) Data traffic needing some guarantees u Interactive data traffic u Frame Relay or ISP Trunks u Key Parameters: PCR & MCR Feedback Loop: Available bandwidth adjusts to network conditions. MCR < Available Bandwidth < PCR

17. ATM Classes of Service n Unspecified Bit Rate (UBR) Data traffic flying standby u EMail u Fax u Fax u Key Parameter: PCR

18. ATM Backbone ATM ‘Cloud’ Trunks use StatMux & Cell Switching CBR trunk traffic may use TDM & Cell Switching ATM Switch Trunks Leased Line

19. ATM Call Admission Control n Procedure for setting up SVC’s & PVC’s n End user requests call set-up Provides destination, CoS, parameters n Switches determine if resourses are available Sufficient Buffer Space? Sufficient unreserved trunk bandwidth? n Call is rejected if insufficient resources

20. ATM n Hookups: WAN see Frame Relay MAN see OSU Backbone LAN see Switched Ethernet n Performance: Depends on the Class of Service

21. ATM Performance 0% 100% Trunk Offered Load Probability of dropped cells *Provided we are following traffic contract UBR ABR* VBR-nrt* & VBR-rt* CBR

22. ATM Performance 0% 100% Trunk Offered Load Delays of delivered cells *Provided we are following traffic contract UBR ABR* VBR-nrt* & VBR-rt* CBR

23. Switched Network Carrying Capacities 0% Data 100% Data 100% TST 0% TST Offered Load Carrying Capacity Circuit Switch TDM Packet Switch StatMux Cell Switch StatMux

24. ATM Status n is flunking at the desktop u Mixed Traffic? No u Speed Advantage? No u $$$ savings? No u PC protocols can’t handle QoS n is succeeding on Carrier Backbones u Mixed Traffic? Yes u Speed Advantage? No (at the moment) u $$$ savings? Competitive

25. U.S. ATM WAN Revenues $0.01B ‘94 $0.03B ‘95 $0.06B ‘96 $.16B ‘97 $0.38B ‘98 $0.00B ‘93 $0.72B ‘99 Source: Data Communications About 3-4 years behind Frame

26. Trunks Leased Line ISP Router Private ATM ‘Edge’ Switch Carrier Voice Switch ATM Backbone Carrying Mixed Traffic. Trunks are more effectively utilized.

27. Frame Relay Backbone A close look at the FR Trunks may reveal that... FR Switch Trunks Leased Line

28. Frame Relay over ATM Trunks Leased Line ATM PVC ISP Router...they are actually ATM Virtual Circuits.

29. Frame Relay over ATM n 7 Application n 6 Presentation n 5 Session TCP n 4 Transport TCP n 3 Network IP n 2 Data Link Frame Relay/ATM n 1 Physical