Call Detail and Call Maintenance Records for

Performance Measurement

•Call Detail Records - CDR: info about the endpoints and control/routing of a call

•Used for billing

•Call Management Record - CMR: info about the quality of the streamed audio of a call

•May have more than one CMR per CDR

•Both CDR and CMR are needed

•Documented by Cisco

Background and Motivation

•1998 Voice over IP with Selsius

•now > 12,000 ethernet VoIP instruments

•Integrated Backbone Architecture

•ATM moving to routed ethernet

•Star of routers - 2 levels

•8 routers at UP

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Service Level for Voice

•Performance SL developed to support voice

•One way latency < 25ms

•Loss < 0.001% packets

•Jitter < 5ms

SL continued

•Model voice traffic and measure it

•Modeled by UDP streams at 85 kbps

•Measured loss, latency and jitter

•Van Jacobson talk/paper about pathchar - MSRI

•using iperf 1.7

QoS for Voice

•Implemented Expedited Forwarding

•To protect the voice traffic

•in 6500/7600 Cisco router

•Compared with best effort vs EF for voice

While at a meeting

•While at a meeting with Cisco about a separate problem, I stumbled upon the fact that the Cisco IP Phones track network statistics

•The phones report loss, latency, jitter, packets and octets sent and received.

•which can be recorded in CDR/CMR

•CMR

So, the next step

•Establish thresholds

•intra system

•phone-to-phone

•Inter-system

•phone-to-someone-else’s-stuff

•This is still a work in progress

•Questions

•Thank you