1 Link-State IGP Data-Plane Convergence Benchmarking draft-ietf-bmwg-igp-dataplane-conv-meth-20 draft-ietf-bmwg-igp-dataplane-conv-term-20 S. Poretsky, Allot Communications B. Imhoff, Juniper Networks K. Michielsen, Cisco Systems March 22, 2010

2 Main changes in -20 Driven by comments received during WGLC Two new optional testcases Accuracy intervals Packet Delay Variation and Rate-Derived Method

3 Two new optional testcases 1 to N path convergence –local failure –remote failure

4 1 to N path convergence local failure Ingress Interface | |< | | | | Preferred Egress Interface | | | | >| | | | ECMP set interface 1 | | | DUT | >| Tester | | |. | | | | >| | | | ECMP set interface N | | Figure 2: IGP convergence test topology for local changes with non- ECMP to ECMP convergence

5 1 to N path convergence remote failure | | | | Preferred | R2 |---->| | | | >| | | | | | Egress Interface | | | | | | | | ECMP set interface 1 | | | R1 | >| Tester | | |. | | | | >| | ECMP set interface N | | ^ | | Ingress Interface Figure 4: IGP convergence test topology for remote changes with non- ECMP to ECMP convergence

6 Accuracy Intervals Calculations: see Loss-Derived Method and Route-Specific Loss- Derived Method [-(number of destinations/Offered Load), +(number of destinations/Offered Load)] Rate-Derived Method –First Route Convergence Time [-(Packet Sampling Interval + time between two consecutive packets to the same destination), +(Packet Sampling Interval + 1/Offered Load)] –Rate-Derived Convergence Time [-(2 * Packet Sampling Interval), +(time between two consecutive packets to the same destination + 1/Offered Load)]

7 Packet Delay Variation and Rate- Derived Method PDV causes fluctuations in the number of received packets per Packet Sampling Interval (PSI) OL 1Mpps 1000 routes PSI 1ms PDV 1ms OL 1Mpps 1000 routes PSI 1ms PDV 10 s

8 Packet Delay Variation and Rate- Derived Method Estimated expected number of packets per PSI after completing Full Convergence: [(PSI - PDV)*OL, (PSI + PDV)*OL] OL=Offered Load PDV=maxDelay - minDelay maxDelay and minDelay measured during PSI draft -20 wrongly uses Jitter [RFC 4689] If too much fluctuation (e.g large PDV with small PSI): enlarge PSI

9 Packet Delay Variation and Rate- Derived Method When are the convergence instants reached? non-ECMP cases: –Convergence Event Instant and First Route Convergence Instant: PDV no/less impact on n 0 and 0 n transitions –Convergence Recovery Instant: reached if #packets within expected range ECMP cases: –PSI = n*(#routes/OL) (n N) to prevent fluctuations of #packets per PSI due to load-balancing

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