Max number of TCP sessions

Max number of TCP sessions

[James Courtier-Dutton]

Hi,

For a host using a Pentium 4 CPU at 2.8Mhz, what is a sensible max value 
for number of TCP sessions this host could run under Linux?
Bandwidth per TCP session is likely to be about 10kbytes/second.

Kind Regards

James

Re: Max number of TCP sessions

[Stephen Hemminger]

On Thu, 16 Nov 2006 20:23:37 +0000
James Courtier-Dutton <James@superbug.co.uk> wrote:

> Hi,
> 
> For a host using a Pentium 4 CPU at 2.8Mhz, what is a sensible max value 
> for number of TCP sessions this host could run under Linux?
> Bandwidth per TCP session is likely to be about 10kbytes/second.
> 

Look at your fundamental limits:

	* how fast is your network interface?
	* how fast is your bus?
	* how much kernel memory is available.


-- 
Stephen Hemminger <shemminger@osdl.org>

Re: Max number of TCP sessions

[Rick Jones]

On Thu, 2006-11-16 at 20:23 +0000, James Courtier-Dutton wrote: 
> Hi,
> 
> For a host using a Pentium 4 CPU at 2.8Mhz, what is a sensible max value 
> for number of TCP sessions this host could run under Linux?
> Bandwidth per TCP session is likely to be about 10kbytes/second.

To a first order, and assuming that there is nearly no user-space
processing for those TCP connections (TCP is a transport not a session
protocol :) you could take a netperf TCP_RR test result - using the
service demand - usec of CPU/KB transferred you could then do some back
of the envelope calculations as to the number of 10 KByte/s connections
you could support.  It would be a bit of handwaving, but give yourself
say a 20% pad and you'll probably be OK.

rick jones

> 
> Kind Regards
> 
> James
> -
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