Hi Tim, Since latency depends on so many factors, audio drivers, buffers in media bridge, ptime, codec, transmission, jitter-buffers etc The build in metrics from PJSUA dq command will give you statistics for jitter, round trip time but this does not take ptime and buffer delay in audio drivers and media bridge into account. Tto get a true feeling we usually do audio tests: 1. Set up two PJSUA clients (or your real clients) with a MIC input on A and a speaker on B 2. Have an external PC with a mic and some audio recording software e.g. audacity and start recording 3. Start a call and try to make a sharp click noise 4. Meassure latency in audacity If you want to see contribution from audio driver connect the speaker to A and use cc 0 0 in pjsua to loop back audio If you want a full roundtrip measurement set B in loop back mode and connect a call and repeat as above. You could also play around with jitter buffer parameters and jitter buffer mode, as well as audio driver latency. Hope this helps a bit. BR/Olle Fr?n: pjsip [mailto:pjsip-bounces at lists.pjsip.org] F?r McLeod, Tim Skickat: den 30 november 2012 16:25 Till: pjsip at lists.pjsip.org ?mne: [pjsip] Measuring Voice Latency We have an urgent need to measure and record the voice latency transmissions using the pjsip User Agent. We have assumed that the in-built jitter measurement is useful to our needs (we also require a jitter measurement). However, my software engineer is unclear how pjsip's inbuilt performance metrics can be used to measure latency, if it can be used at all. Your help in this matter would be very much appreciated. Many thanks... Tim McLeod MBCS CITP Principal Engineer Tel: +44 1633 715097 Mob: +44 7765 088364 Email: tim.mcleod at cassidian.com<mailto:tim.mcleod at cassidian.com> RLI: tim.mcleod at eads.r.mil.uk<mailto:tim.mcleod at eads.r.mil.uk> Website: www.cassidian.com<http://www.cassidian.com/> The information contained within this e-mail and any files attached to this e-mail is private and in addition may include commercially sensitive information. The contents of this e-mail are for the intended recipient only and therefore if you wish to disclose the information contained within this e-mail or attached files, please contact the sender prior to any such disclosure. If you are not the intended recipient, any disclosure, copying or distribution is prohibited. Please also contact the sender and inform them of the error and delete the e-mail, including any attached files from your system. Cassidian Limited, Registered Office : Quadrant House, Celtic Springs, Coedkernew, Newport, NP10 8FZ Company No: 04191036 http://www.cassidian.com ________________________________ No virus found in this message. Checked by AVG - www.avg.com<http://www.avg.com> Version: 2012.0.2221 / Virus Database: 2634/5427 - Release Date: 11/29/12 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20121205/d3f81bfe/attachment-0001.html>
