1. Traffic Engineering and Routing Hansen Bow

2. Topics Traffic Engineering with MPLS Issues Concerning Voice over IP Features of Netscope QoS Routing for High-Speed Networks QoS Routing for Multimedia

3. Traffic Engineering with MPLS: Methods MPLS – multiprotocol label switching Constraint-based routing Enhanced link state IGP

4. MPLS-multiprotocol label switching forwarding scheme at ingress of MPLS network, IP packets are classified, tagged, and routed at next router, tag is used to determine destination before leaving, tag is removed

5. Constraint-Based Routing computes bounded routes reservable bandwidth of a link is an approximation can be done online or offline

6. Enhanced Link State IGP (interior gateway protocol) distribute link information flood network to obtain information

7. Deploying MPLS System (GlobeCenter) Statistics Collection Deploy LSP (label-switched path) with bandwidth constraint Periodic update of LSP Bandwidth Offline Constraint-Based Routing

8. Voice over IP Issues modify capacity management and routing methods in IP to support IP telephony –delay less than 300ms –loss rate <1% First Model: RSVP Second Model: voice service uses Virtual Private Network

9. RSVP Routing Shortest Path First Shortest Available Path First Widest Available Path First

10. Virtual Private Networks interconnects telephony switches Direct Path Only Success to the Top State-Dependent Routing Approximate State-Dependent Routing

11. Direct and Alternate Routing Policies

12. Differently Routed Calls with Trunk Reservation

13. Routing Policies with Integrated Services Model not much difference between SPF, SAPF, WAPF fewer blocked calls for a given network capacity because of better sharing of network capacity

14. Features of Netscope traffic measurement and network modeling provide global views of configuration and useage data

15. Utility of Netscope realizing customer SLAs tuning parameters of network components unite configuration experiment with possible solutions to variable complex traffic

16. Data Network components Modeling Traffic Routing –multiple shortest paths

17. Visualization Objects Statistics Traffic and Links Changing Routes

18. QoS Routing Issues for High Speed Networks Goals –satisfy QoS requirements for admitted connection –global efficiency Classes –Source routing –Distributed routing –Hierarchical routing

19. Routing Collection of State Information –local and global state –aggregated global state

20. Routing Finding Feasible Path –Unicast link optimization link constrained path optimization path constrained –Dijkstra’s algorithm http://www.cs.uwa.edu.au/undergraduate/courses/230.300/read ings/graphapplet/graph.htmlhttp://www.cs.uwa.edu.au/undergraduate/courses/230.300/read ings/graphapplet/graph.html –Multicast Steiner Tree

21. Routing Strategies Source routing –centralized problem, loop-free –need global state, computation overhead Distributed routing –routing response faster, scalable –need global state, more messages, loops Hierarchical routing –scales well, computation shared –imprecision because aggregate state, complicated with constraints,

22. Future Directions Efficient Routing Algorithms Routing with imprecise state information Multipath Routing Rerouting

23. QoS Routing for Multimedia Metric Selection –Efficient algorithms must exist for path computation –Reflect basic information of network –orthogonal Multiple Metrics –additive, multiplicative, concave

24. Bandwidth and Delay as Metrics finding path subject to two or more additive and multiplicative metrics is NP-complete only feasible combination is bandwidth and, for example, delay

25. Path Computation Algorithms Source Routing Hop-by-hop –compute best path to every destination –shortest-widest path is free of loops

26. References “NetScope: Traffic Engineering for IP Networks,” A. Feldmann, A. Greenberg, C. Lund, N. Reingold, and J. Rexford, IEEE Network, Mar./Apr. 2000, pp. 11-19 “Traffic Engineering with MPLS in the Internet,” X. Xiao, A. Hannan, B. Bailey, and L.M. Ni, Ibid., pp. 28-33 “Capacity Management and Routing Policies for Voice over IP Traffic,” P.P. Mishra, and H. Saran, Ibid, pp. 20-27 “Quality-of-Service Routing for Supporting Multimedia Applications,” Z. Wang, and J. Crowcroft, IEEE Journal on Selected Areas in Communications, Vol. 14, No. 7, Sept. 1996 “An Overview of Quality of Service Routhing for Next-Generation High-Speed Networks: Problems and Solutions,” S. Chen and K. Nahrstedt, IEEE Network, Nov./Dec. 1998, pp. 64-79