On Mar 23, 2024, at 5:14 PM, Ovidiu Sas osas@voipembedded.com wrote:
But if you are dealing with network jitter and several clients pumping traffic at different rates, for a short period of time all the workers will be busy while new SIP messages will pile up and the default queue will not be able to hold all of them.
Absolutely. I'm just not convinced that you want to hold them in most situations.
An increased UDP queue will hold all the SIP messages giving time the workers to consume them. The idea is that you have the UDP queue empty all most of the time, and only when there’s a short temporary traffic burst, it will come to the rescue.
If the UDP queue of full most of the time, then increasing it obviously won’t help. The increased UDP queue works only for coping with short traffic bursts.
100% agree, if short, relatively infrequent stochastic bursts are the specific problem to be solved.
It's just that OP is testing with SIPp, which doesn't send that kind of burst. It sets up calls at a pretty constant rate, distributed uniformly throughout the temporal domain. So, the scenario being simulated there is indeed a UDP queue that is full most of the time, under a +/- constant base load.
My argument was implicitly tailored to the idea that if your base load is excessive, a bigger queue won't help. I definitely agree with you that increasing rmax can take the edge off some ephemeral bursts.
-- Alex