[asterisk-dev] Asterisk scalability

[Ian FREISLICH]

Benny Amorsen wrote:
> Johansson Olle E <oej at edvina.net> writes:
> 
> > With SIP (for some reason, I did not test IAX2 ;-) ) we clearly see
> > that the system dies around 1600 simultaneous channels being trashed
> > by all the RTP traffic using the p2p rtp bridge. irqbalance fails
> > miserably at that point and lack of call quality makes all calls
> > sound like the Swedish chef. Unusable is a good description.
> 
> > My conclusion so far is the same as Stephen Uhler's at the Atlanta
> > Astridevcon - the IP stack is our problem here.
> 
> The IP stack itself can only do so much here... At 1600 simultaneous
> calls and 20ms packets, that is 80000pps. The ethernet card will do
> interrupt mitigation at that point, but AFAIK no ethernet card has any
> kind of UDP receive offload.

80kpps is not that much.  I have machines capable of handling just
shy of 1Mpps on 1 physical interface, the main problem is the
physical medium.  My measured max rate on 100M ethernet is 148kpps
using UDP with a payload of 1 byte.  You should be able to get that
packet rate in on gigE with a real-world payload.

Ian

--
Ian Freislich