I've been waiting to talk about this one for a while.
Several months ago Star2Star was having problems with one of our upstream SIP carriers. We were starting to notice a large increase in the number of one way audio calls our customers were reporting.
When most people think of one way calls their first reaction is to blame SIP. Must be NAT! Must be a firewall! SIP sucks! Etc, etc.
I knew that wasn't the case. I just had to prove it.
I was convinced the problem wasn't SIP/UDP/IP related at all. We had multiple pcaps where we were sending RTP to the appropriate gateway. It just wasn't getting to the PSTN. Where was it going? When was this happening? Which gateways (out of hundreds) were the most problematic? We needed to know and we needed to know quickly.
I came up with and "wrote" recqual over a couple of days. After a few runs we were noticing patterns with problematic RTP endpoint IP addresses. Long story short, once these were identified we worked with the carrier to replace various bits of equipment (DSPs, line cards, etc). The one way audio problem has largely disappeared and we continue to run recqual. If this starts happening again we should know /BEFORE/ our customers do.
Of course I'm using Asterisk to place the calls. The best part of using Asterisk is it's multi-protocol flexibility. You should be able to test just about any combination of voice technologies - G.279a, G711, GSM, SIP, IAX, PRI, FXO, FXO, gtalk/jabber/jingle, skype, etc. The possibilities boggle the mind.
I've just been too busy to get it together and release this to the community - until now.
Tarball with instructions here.
Questions? Comments? Suggestions? Drop me a line.
I created AstLinux but I write and rant about a lot of other things here. Mostly rants about SIP and the other various technologies I deal with on a daily basis.
Monday, December 22, 2008
Sunday, December 21, 2008
Consulting Time Available
I haven't blogged in a while but there is some good news...
I have made some time available for consulting work!
You might not be as excited about it as I am but this is a good thing. I'm looking for interesting projects, people, and companies to work with.
If you or anyone you know might be interested please contact me. Resume, references, etc available on request.
I'll be offering bonus time, discounts, and a few other potential incentives to anyone that lets me blog about my projects and/or release any work under a liberal (read: FOSS) license.
Between my change in schedule and some (hopefully) fun new projects you can all expect to see much more frequent blogging soon!
I have made some time available for consulting work!
You might not be as excited about it as I am but this is a good thing. I'm looking for interesting projects, people, and companies to work with.
If you or anyone you know might be interested please contact me. Resume, references, etc available on request.
I'll be offering bonus time, discounts, and a few other potential incentives to anyone that lets me blog about my projects and/or release any work under a liberal (read: FOSS) license.
Between my change in schedule and some (hopefully) fun new projects you can all expect to see much more frequent blogging soon!