Discussion Items for Inter-Provider Service Performance Metrics Ralph Santitoro CTO Office Inter-Provider QoS Workshop at MIT October 20-21, 2004

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 1 Key Service Performance Metrics Rate of Service (RoS) / Bandwidth Profile –Octet count per UNI/NNI, CoS aggregate or Flow per time Performance of Service (PoS) –One Way Packet Delay (also looking at Round Trip) –Packet Delay Variation –Packet Loss Ratio Availability of Service (AoS) –% of time PoS PMs are met over time interval Need Common Terminology, Definitions and Parameters

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 2 Bandwidth Profile Parameters Let’s agree on some common definitions for rate enforcement parameters 4 main parameters for each type of bandwidth profile – CIR/CBS determines packet delivery per PoS objectives EIR/EBS determines amount of excess packet delivery CM (Color Mode) determines the whether packet color markings per CoS should be honored or ignored –EIR ≠ PIR, EBS ≠ PBS –PIR = CIR+EIR Common Definitions and Terms for Rate Enforcement

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 3 Color Indications Green –Packets conformant to CIR/CBS and SLA applicable per PoS parameters (delay, delay variation and loss) Yellow –Packets not conformant with CIR/CBS but conformant with EIR/EBS and SLA not applicable –Packets admitted to network but may be dropped under congestion Red –Packets not conformant to CIR/CBS or EIR/EBS –Packets typically dropped but may be admitted to network Red packets get dropped ahead of yellow packets

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 4 Rate Enforcement / Color from a Token Bucket Perspective Common parameters / definitions result in consistent service performance Metro Ethernet Forum trTCM algorithm for Ethernet services –MEF 5 tech. spec. – Applicable to Ethernet and IP services > CBS > EBS C E New token added CIR/8 times/second New token added EIR/8 times/second Packets arrive at NNI Packets accepted at NNI ≤ CBS ≤ EBS Color-Blind NNI Color-Aware NNI

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 5 NNI Bandwidth Profiles MEF has defined these for UNI. Some possible NNI variants below BW Profile to use depends upon type of service supported at NNI NNI S1S1 S2S2 S3S3 BWP Per NNI Useful for single CoS for all services NNI CoS 1 CoS 2 CoS 3 BPW Per CoS 1 Aggregate BWP Per CoS 2 Aggregate BWP Per CoS 3 Aggregate Useful for services with similar performance requirements, e.g., Gold/Silver/Bronze IP VPN NNI S1S1 CoS 6 BWP Per Subscriber CoS 6 CoS 4 CoS 2 BWP Per Subscriber CoS 4 BWP Per Subscriber CoS 2 S2S2 Useful for services requiring stringent, common performance among subscribers, e.g., VoIP service Is this really needed at NNI?

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 6 Performance of Service (PoS) Packet Delay (One Way) –P percentile of the delay of all successfully delivered Green packets per CoS over time interval T –E.g., PD = 100ms 99.9% over 5 min. intervals Packet Delay Variation (a.k.a. jitter) –P percentile of the difference of delays of green packet pairs within time interval T with inter-packet time interval of Δt –Selection of Δt related to application –E.g., PDV = 5ms 99.9% over a 5 min. intervals, Δt = 5ms Packet Loss Ratio –Ratio of number of discarded green packets during time interval T to number of ingress green packets during the time interval T –E.g., PLR = 0.1% over a 5 min. intervals

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 7 POS PM Zoning Zoning used with PoS PMs to factor in delay introduced due to distance ZoneDistance 100 km Metro 1,000 km Regional 5,000 km National 10,000 km Continental >50,000 km Global PoS PMs in SLA based on Zone Access / Aggregation 10 km

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 8 Performance of Service (PoS) Time Sync / Stamping Critical for one way delay/delay variation measurements IEEE 1588 highlights ( –Provides a deterministic injection and extraction of timestamp information at source and destination MACs to distribute frequency & optional phase aligned clock reference –Sync messages sent at source (master) to end points (slaves) MAC injects precision timestamp –or- Follow-up message sent containing precise master sending time –All slaves compute offset and correct their clocks –Can be sent as UDP/IP packets or as native Ethernet packets Stratum traceable reference over a packet network

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 9 Availability of Service (AoS) Calculated via the following over time interval T –Packet Delay, Delay Variation and Loss Ratio performance objectives being met –UNI or NNI (L1) availability E.g., AoS = 99.9% calculated over 15 minute intervals Would be useful to have BCP guidelines for interval T / CoS –T differs depending upon CoS performance objectives

Inter-Provider QoS Workshop – Service PMs – October 22, Santitoro 10 PM Service Attribute Summary Service Attribute PM descriptionParameters PoS Packet Delay (ms) P percentile, T measurement interval Packet Delay Variation (ms) P percentile, T measurement interval Packet Loss Ratio (%) P percentile, T measurement interval Δt inter-packet time interval RoS Bandwidth Profile per NNI Bandwidth Profile per CoS Aggregate Bandwidth Profile per Subscriber CoS AoSPD, PDV, PLR SLOs being met (%)T measurement interval