[Asterisk-Users] newbie question regarding asterisk

[Tom Rymes]

On Nov 14, 2005, at 6:21 AM, Markos Paraskevopulos wrote:
> Hello everyone,
>
> I’m new to VoIP and despite a lot of reading, I’m kind of more  
> confused than before.
>
> I have following question – we currently have hardware Alcatel PBX  
> and approx. 50 phones in the company. I was wondering if we would  
> need to change the phone service provider, because they don’t  
> provide VoIP services if we were about to switch to Asterisk  
> instead of the Alcatel PBX?
>
> Or can Asterisk maintain current functionality plus adding VoIP by  
> simply switching the alcatel pbx for Asterisk server?
>
> I hope I’m making at least a bit of sense.
>
>  Thanks in advance for help
>
> Confused
>
> Markos
Markos,

The answer to your question is "Maybe". It depends on how you connect  
your existing PBX to the PSTN, and it depends on what you want from  
your system.

Asterisk is completely capable of connecting to standard analog and  
digital (T1/E1/PRI) phone circuits. You do not need to use VOIP to  
connect Asterisk to the phone network. However, how you will go about  
doing this depends on your call volume and budget. How many incoming/ 
outgoing phone lines you have, how much long distance you dial, and  
local telco rates all play a part here.

The easiest way is to figure out how you connect the existing PBX,  
and then you can research to see if Asterisk will support that  
technology. (Chances are that it does). For example, if your Alacatel  
connects to the PSTN via a T1/E1 Circuit, then you could buy an T1/E1  
interface card from Digium or Sangoma and plug the T1/E1 right into  
your Asterisk server. If you have multiple analog POTS lines, then  
it's more complicated, but there are solutions for that, too (digium  
X100P, TDM400p, TDM2400p, various SIP gateways, multiple Sipura  
SPA-3000, etc...)

Then you might want to research your other options and make sure that  
you are using the most cost effective solution for your needs (This  
all depends on how you use the PSTN and what the local rates and  
availability are). The most basic knowledge you will need is the  
difference between a T1/E1 style connection and a regular analog POTS  
line. For example, if you have multiple analog lines, you might be  
able to save money by getting a full or fractional T1/E1.

If you're still completely confused and you don't have a lot of  
telecom knowledge, you might want to consider hiring a consultant to  
help you out.

Tom

----------------------------------------------------------
Tom Rymes
Cascade Link Systems
www.cascadelinksystems.com
(603) 375-1414

Technology solutions for small and medium sized businesses.