[Spce-user] SEMS SBC CPU question

[Stefan Sayer]

Hi,

is SEMS actually handling (relaying) RTP for those calls?

looks like in the used SEMS version there's only one thread (the RTP
receiver thread) handling relay of RTP packets, and also there's only
one thread receiving SIP packets. The media_processor_threads process
(decode, write, mix etc) and send RTP, the session_processor_threads
process received SIP packets and send SIP messages.

In newer SEMS versions (git master), we have:

sip_server_threads - receive SIP packets, parse them
session_processor_threads - process parsed SIP messages, run
                   session logic, send SIP messages
rtp_receiver_threads - receive RTP, relay RTP (sbc module)
media_processor_threads - process RTP, local audio (e.g. mix), send RTP

So it can be tuned appropriately.

hth
Stefan


o Andrew Pogrebennyk on 02/14/2014 10:52 AM:
> Hi Larry,
> 
> We've seen that 10 media processor threads create some CPU load even
> when sems is idle on the VM, so for development VMs we decreased it to
> 1. You could also try changing the session_processor_threads.
> 
> Other parameter is sip_server_threads, but AFAIK it's just a number of
> SIP UDP receiver threads and it's 8 by default which is quite
> reasonable. Please try to watch the size of Recv-Q and Send-Q in netstat
> -anu as you run the test. You'll see if the bottleneck is in the number
> of SIP or RTP receiving threads.
> 
> P.S. Here's the description from sems core sems.conf.sample:
> ############################################################
> # tuning
> 
> # optional parameter: session_processor_threads=<num_value>
> #
> # - controls how many threads should be created that
> #   process the application logic and in-dialog signaling.
> #   This is only available if compiled with threadpool support!
> #   (set USE_THREADPOOL in Makefile.defs)
> #   Defaults to 10
> #
> # session_processor_threads=50
> 
> # optional parameter: media_processor_threads=<num_value>
> #
> # - controls how many threads should be created that
> #   process media - on single-processor systems set this
> #   parameter to 1 (default), on MP systems to a higher
> #   value
> #
> # media_processor_threads=1
> 
> On 13/02/14 18:06, Schaefer, Larry wrote:
>> Andreas,
>>
>> Thanks for the response... I have been modifying media_processor_threads in sems.conf, but so far it does not seem to make a difference.  I am still wondering if running in Amazon EC2 is part of the issue.  
>>
>> Wondering if anyone has experience with running SEMS in EC2 and if they are seeing any similar problems with CPU.  
>>
>> Any additional advice or suggestions would be appreciated...
>>
>> Thanks,
>> Larry 
> 
> 
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