Le 2015-08-27 17:00, Moises Silva a ?crit :
I'm curious. Can you be more precise on what you mean exactly by generic 1U server? What matters mostly is the processor, not the rack unit, so I'd be interested in hearing your experience with transcoding 5000 g729 to g711 channels.
I'm sorry, I can't, for obvious reasons.
Here are some precise numbers that I run on a dual xeon 1U server earlier this month for a presentation at the FreeSWITCH conference, ClueCon.
The tests were run using 1,000 calls at 50cps (using FreeSWITCH). However, I did test at lower cps, same max calls and results are quite similar because the bulk of the load is the transcoding
That is my experience as well.
as it can be seen in the graphs below.
Without transcoding (just PCMU to PCMU bridging with standard 20ms packetization):
http://moythreads.com/vmstat/xeon-sqlitefullmem-lwarn-sprof-glibc-1000 at 50cps/report.html
And with G.722 to PCMU transcoding:
http://www.moythreads.com/vmstat/xeon-sqlitefullmem-lwarn-sprof-glibc-transc... at 50cps/report.html
At 1,000 calls you already maxed the CPUs with G.722 transcoding, see the last graph, that's what's more relevant, showing how the idle cpu on the server went from 80% to 15% idle on average just when adding transcoding. Granted, there's more powerful boxes out there, but this should give people a clear idea of the cost of transcoding.
...on FreeSWITCH. I'd be curious to see the output of "perf top", to see if CPU time is being spent wisely.
The algorithmic complexity of G722 is on par with G.729, in fact, G.729 is a bit more complex.
That is my experience as well. Simon