Call Detail and Call Maintenance Records for Performance Measurement

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