Call Detail and Call Maintenance Records for Performance

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 Vo. IP instruments • Integrated Backbone Architecture • ATM moving to routed ethernet • Star of routers - 2 levels • 8 routers at UP

Text

Text

Service Level for Voice • Performance SL developed to support voice • One way latency < 25 ms • Loss < 0. 001% packets • Jitter < 5 ms

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

Qo. S 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