[asterisk-users] PSTN to SIP line ratio

[Tim Nelson]

----- "Steve Edwards" <asterisk.org at sedwards.com> wrote:
> On Thu, 15 Oct 2009, Shahnawaz Mir wrote:
> 
> > I am planning to deploy an Asterisk PBX for 100-200 users. I am not
> sure 
> > about PSTN incoming/outgoing line ratio for SIP users. I mean if you
> 
> > recall dial up internet the common line ratio is 1:10 (one line for
> 10 
> > users on access server or an E1 for 300 users). Can somebody tell me
> 
> > what is the good ratio for incoming and outgoing analogue/ digital
> PSTN 
> > lines.
> 
> 42[:1]
> 
> (The fact that you ask such a generic question implies you have a high
> 
> probability of failure. You should hire somebody with a bit more clue
> and 
> learn from them.)
> 
> -- 
> Thanks in advance,
> -------------------------------------------------------------------------
> Steve Edwards       sedwards at sedwards.com      Voice: +1-760-468-3867
> PST
> Newline                                              Fax:
> +1-760-731-3000
> 

Ignoring unhelpful snobbish remarks from the peanut gallery...

Your ratio will depend largely on the usage by your users. In a busy contact center where your users/agents will be on calls nearly 100% of the time, your ratio will need to be closer to 1:1. However, if the installation is for a school where most of the staff (teachers) are instructing in the classroom or otherwise away from their desks, you can get by with a higher ratio like 4:1.

As always, you build your system with room for expansion in the event you need additional resource availability. Also, ensure your customer/client understands the limitations of the number simultaneous calls. If you don't tell them and they find out the hard way, you'll be in a world of hurt.

Tim Nelson
Systems/Network Support
Rockbochs Inc.
(218)727-4332 x105