[Asterisk-Users] Traffic Modelling (was IVR only system with scalibility...)

[PJ Welsh]

Nice goin'!! I will use this for a reference point to establish baseline numbers of phone lines. The good news is that the equation is not linear (eg 45 people need 5 lines, 100 need 10 lines). So I can double my potential users and ONLY need 2 more lines (qty 7). The bad news is that I don't 100% think I will have purely random connections. 

On Thu, Sep 04, 2003 at 12:48:58PM -0700, George Pajari wrote:
> The question was posed:
> 
> "incomming calls for 45 or so people that will call in 3 or 4 time each 
> day during (approx) normal business hours"
> 
> The comment was made (taken out of context):
> 
> "The quick math says that 45 people with 4 calls is 180 calls a
> day. In a 8 hour day you have 480 minutes. From 480 minutes 1 port could
> handle the load if the call was under 2.5 minutes long and everyone
> waited till it became available."
> 
> Unfortunately as we all know, asking callers to guess when the line is 
> free and equally spacing their calls is not terribly realistic (as the 
> author of the comment above goes on to imply).
> 
> So how does one analyse such a situation? Using statistical traffic 
> modelling!
> 
> For more information, see http://www.erlang.com/calculator/erlb/
> 
> Plug in:
> 	Busy Hour Traffic: 0.937 Erlangs
> 	(based on 45 * 4 * 2.5 / 480)
> 
> 	Acceptable Blocking Factor: 1%
> 	(we will accept 1 in 100 calls receiving a busy signal)
> 
> Result:
> 	you will need 5 incoming lines.
> 
> If you are willing to tolerate (say) 3% of calls receiving a busy 
> signal, you can get by with 4 lines etc. and etc.
> 
> Hope you find the above useful in planning your Asterisk installation.
> 
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