[Freeswitch-users] Fwd: Strategies for testing latency

[Darren Schreiber]

Hi folks,
This may be a slightly off-topic FreeSWITCH question, but here goes...

I am having issues trying to figure out the source of latency in circuits we LCR to, it seems to be somewhat of a guessing game. I am embarking on creating a tool to measure this latency so we can test carriers more rapidly when deciding whether to use them or not.

Before I re-invent the wheel, I'd love to know what others do to ensure latency is at a minimum on the circuits they buy from carriers OR if there are specific things to tweak in FreeSWITCH that I'm unaware of that somehow would help this. I can't imagine there are, but maybe I've missed something.

It is my belief that some of the carriers we are using are behind Asterisk boxes that are always taking on media and are adding an encode/decode step to the path, resulting in some latency, as I can't find any evidence of late packets or high jitter on our box <-> carrier.

For us, latency seems most noticable when we have callers on cell phones using a conference bridge. The latency nears 800-1000ms from when a person speaks to when they are heard on the other cell phone. I have tried to tweak our own conference bridge settings but I really don't think that's going to make a difference if my theory of the issue being upstream is correct. VoIP <-> VoIP conferencing has none of this issue.

Any experience that folks can offer here is appreciated. Obviously getting a direct RTP stream from the carrier doing the conversion to PSTN would be best, but it has a tendency to require a lot of minutes or be expensive to do yourself.


Thanks,

Darren Schreiber
Co-Founder - the 2600hz Project
(415) 886-7900 - www.2600hz.org<http://www.2600hz.org/>

Join us in January for FreeSWITCH Training in Australia!
Visit www.voipkb.com<http://www.voipkb.com/> for more information



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20101102/9836ca90/attachment.html