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International Conference on Communications (ICC 2004)

International Conference on Communications (ICC 2004). Enhancing fault management performance of two-step QoS routing algorithms in GMPLS networks. Eusebi Calle, Jose L Marzo, Anna Urra. L. Fabrega. eusebi@eia.udg.es. Universitat de Girona. Contents. Background (Fault Management)

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International Conference on Communications (ICC 2004)

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  1. International Conference on Communications (ICC 2004) Enhancing fault management performance of two-step QoS routing algorithms in GMPLS networks EusebiCalle, Jose L Marzo, Anna Urra. L. Fabrega eusebi@eia.udg.es

  2. Universitat de Girona Contents Background (Fault Management) The failure probability and impact Two-step and one-step routing methods Experimental results Summary and conclusions

  3. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions 2 4 6 8 Backup LSP 1 3 5 7 9 PSL Node PML Node FIS : Fault Indication Signal Working LSP • Protection Switch LSR (PSL) :switches protected traffic from the working path to the corresponding backup path. • Protection Merge LSR (PML) :merges their traffic into a single outgoing LSP, or, if it is itself the destination, passes the traffic on to the higher layer protocols. 1. Fault Management 1.1 MPLS/GMPLS fault management.

  4. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Backup LSP Working LSP 2 4 6 8 1 3 5 7 9 1. Fault Management 1.2 Classes of impairments IETF RFC3469 Path Failure (PF) ... Path Degraded (PD)... Link Failure (LF) is an indication from a lower layer that the link over which the path is carried has failed. If the lower layer supports detection and reporting of this fault, i.e. any fault that indicates link failure for example SONET Loss of Signal (LoS), this may be used by the MPLS recovery mechanism. Link Degraded (LD) ... SINGLE LINK FAILURES

  5. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions 1. Fault Management 1.3 The M:N model M is the number of backup LSPs used to protect N working LSPs 1:1: 1 working LSP is protected/restored by one backup LSP. M:1: 1 working LSP is protected/restored by M backup LSPs. 1:N: 1 backup LSP is used to protect/restore N working LSPs (shared backups). M:N : N working LSPs are restored by M backup LSPs 1:0 : No protection (for instance, Best effort traffic) 1+1: Traffic is sent concurrently on both the working LSP and the backup LSP. 1:1 M:1 1:N M:N 0:1 1+1 Backup Paths Working Paths

  6. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Computed on demand Path Provisioning Established on demand Pre-computed Resource pre-allocated Pre-established Resource allocated on demand Dedicated (1:1 or 1+1) Resource allocation Shared (1:N, M:N) No resources (1:0) 1. Fault Management 1.4 a) Path provisioning classification 1.4 b) Resource allocation classification

  7. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Advantages Disadvantages Slow Failure Recovery Time Path Protection ( 1 PSL, 1 PML ) Packet Loss 1. Fault Management 1.5.a) Global Backup Path Global Backup Path 2 4 6 8 1 3 5 7 9 Ingress node PSL Egress Node PML Working Path

  8. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Advantages Disadvantages Path Protection Slow Failure Recovery Time Low Packet Loss Packet reordering High Resource Consumption 1. Fault Management 1.5.b) Reverse Backup Path Global Backup Path 2 4 6 8 1 3 5 7 9 Ingress node Egress Node Working Path Reverse Backup Path

  9. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Advantages Disadvantages Fast Failure Recovery Time High Resource Consumption (Path Protection) Low Packet Loss 1. Fault Management 1.5.c) Local Backup Path Local Backup Path 2 4 6 8 1 3 5 7 9 Ingress node Egress Node Working Path

  10. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Segment Backup Path 2 4 6 8 1 3 5 7 9 Ingress node Egress Node Working Path Advantages Disadvantages 1. Fault Management 1.5.d) Segment Backup Path

  11. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Path 1 2 4 6 8 1 3 5 7 9 Ingress node Egress Node Path 2 Advantages Disadvantages Path Protection High Resource Consumption Very Low Packet Loss Fast Failure Recovery Time 1. Fault Management 1.5.e) 1+1 Protection

  12. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions • Drawbacks and lacks • No protection considerations -> Secondary routing objective (No specific backup routing information) • High complexity (in terms of computation time) • High resource consumption (1+1) • No traffic differentiation • No physical network considerations (availability and reliability) • Failure impact (fault recovery time, packet loss…) • Objectives • Protection as a main routing objective • Low complexity • Low resource consumption • Traffic differentiation • Failure Probabilities • Reducing Failure Impact 2. Reducing failure probability and impact 2.1. Enhanced fault recovery methods for protected traffic services in GMPLS networks

  13. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Recovery phase Fault detection (TDET) Hold off time (THOF) Notification time (TNOT) New Backup creation (TBR + TBS) Backup Activation (TBA) Switchover (TSW) Complete recovery (TCR) Features Depends on the technology Depends on the lower layers Depends on the Failure Notification Distance and notification method Depends on the routing and signaling method applied Depends on the backup distance and signaling cross-connection process Depends on the node technology Depends on the backup distance Time Reduction Cannot be reduced (except in the case of monitoring techniques) Setup (0-50 ms) Minimizing the Failure Notification Distance and optimizing the process Pre-establishing the backup Minimizing the backup distance and optimizing the process Cannot be reduced Minimizing the backup distance 2. Reducing failure probability and impact 2.3 Minimization of the failure recovery time (Failure Impact) IETF CCAMP Common Control and Measurement Plane Intenet Drafts Rabbat, Sharma...

  14. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Current Link Failure Probability LFP Statistical Failure Values LFP1 LFP2 LFP3 LFPN N å = LSP _ FP LFP i = i 1 2. Reducing failure probability and impact 2.4 Failure Probability Label Switch Path Failure Probability Geographical Conditions Network Components Initial Link Failure Probability Failure Probability Models: MIL-HDBK-217 Bellcore/Telcordia MTTR MTBF FR Label Switch Path ….

  15. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions 2 4 6 2 4 6 Local Backup 1 3 5 7 1 3 5 7 Working path Working path RFP = (1+4)= 5= LFP RFP = 1 2 4 6 2 4 6 Local Backups Segment Backup 1 3 5 7 1 3 5 7 Working path Working path RFP = 0 RFP = 0 2 4 6 2 4 6 Global Backup 1+1 1 3 5 7 1 3 5 7 Working path RFP = 0 Working path RFP = 0 2. Reducing failure probability and impact 2.5 Residual Failure Probability Residual Label Switch Path Failure Probability LFP = 1·10-4 LFP = 4·10-4

  16. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Separated Links to be protected Consecutive links to be protected 2 4 6 2 4 6 2 4 6 2 4 6 Local Backups Local 2 4 6 Segment 1 3 5 7 1 3 5 7 Global Backup 1 3 5 7 1 3 5 7 1 3 5 7 Working path Working path Working path Working path Working path 2 4 6 2 4 6 2 4 6 Local Backup Global Backup Local 1 3 5 7 1 3 5 7 1 3 5 7 Working path Working path Working path 2. Reducing failure probability and impact 2.6 Case Study High Failure Probability Low Failure Probability

  17. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions 2. Reducing failure probability and impact 2.7 GMPLS Protection with traffic differentiation Protection assignment for class types based on the network failure probability and failure impact Protected Traffic services • High-resilience requirement traffic services: Traffic that is very sensible to network faults (like EF diffserv traffic). Residual Failure probability and Failure Impact values should be set up at zero. 1+1 or local backup paths can be used in order to accomplish these values. • Medium-resilience requirement traffic services: Traffic that is sensible to network faults (like AF1 or AF2 diffserv traffic). However, resource consumption should be taken into account to route the working and backup paths. Residual failure probabilities and failure impact values should be bounded in order to achieve the desirable QoS with appropriate resource consumption. Segment and global backups can be used to protect these services. Non-Protected Traffic services • None-resilience requirement traffic services. No protection requirements are needed (BE traffic).

  18. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions One-step routing 2 4 Backup Path 1 3 5 7 2 4 Working path 1 3 5 7 6 8 Shortest Working Path Working path 6 8 Two-step routing Advantages 2 4 Smart Protection Backup Path Fast Recovery Time 1 3 5 7 Low Packet Loss Low Resource Consumption 6 8 Low Failure High Failure Low Failure Probability Probability Probability 3. Two-step vs One-step routing algorithms 3.1 Two-step versus One-step routing Trap Topologies (MHA + Global Protection)

  19. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions 10 - 4 6 5 4 failure probability 3 Non Protected Traffic 2 LSP Protected Traffic No Traffic Differentiation 1 0 Time Number of LSP 0.2 No traffic differentiation 0.18 Protected Traffic 0.16 Request Rejection Ratio 0.14 0.12 0.1 0.08 0.06 1 2 3 4 5 6 7 8 9 10 Failure Probability Distribution Trial Number 4. Experimental results 4.1 Failure Probability Analysis (*) Failure Probability evaluation. Traffic differentiation. Dynamic Traffic Failure Probability evaluation. Traffic differentiation. Incremental Traffic Residual Failure Probability evaluation. Request Rejection Ratio No protection Incremental / Dynamic exp. Traffic Differentiation Modified WSP

  20. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions 4. Experimental results 4.2 Residual Failure Probability Analysis Residual Failure Probability evaluation. Segment Backups and traffic differentiation. Residual Failure Probability evaluation. Local Backups and traffic differentiation. Time Time Local and segment protection Dynamic traffic, Traffic Differentiation, Modified WSP Similar RFP, Local (more resource requirements) but minor failure impact.

  21. Contents 1. Fault Management 2. Reducing failure probability/ impact 3. Two-step versus One-step routing 4. Experimental results 5. Summary and Conclusions Quality of protection degree Failure Impact Minimum Failure Notification Network Availability and Reliability Failure probability evaluation models Minimum Residual Failure Probabilities Resource Consumption Minimum resource consumption (Segment + Probabilities) Protected-Traffic Services Enhanced routing algorithms Two-step routing methods 5. Summary and conclusions 5.1 Summary and conclusions

  22. Thank you ! International Conference on Communications (ICC 2004) Enhancing fault management performance of two-step QoS routing algorithms in GMPLS networks EusebiCalle, Jose L Marzo, Anna Urra eusebi@eia.udg.es

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