Routing calls to PSTN

Hey Guys,

I just need a little help with my VOIP network. I have a SIP proxy server and 4 SIP phones connected to the server. Locally everything works great no problem. I want the Asterisk PBX to connect to the PSTN to I can make outgoing calls and recieve calls as well. There is an option on the SIP server for PBX. I just want to know if I buy the FXO card and connect to PSTN network I am using the Lines thats provided by the telephone provider so that means I have to pay them the charges. I short I have some questions:

  1. I am here in canda and the PSTN lines are owned by Bell if I route calls to PSTN Do I have to pay them for same long distance charges since I am using Bell lines?

  2. Is there an alternat way to overcome that?

I am just a little confused please clarify…


  1. yes, if you connect your PBX to the PSTN via standard POTS lines, you will be charged the same as if you hooked a standard handset up.

  2. yes, use an ITSP (internet telephony service provider) to connect to the PSTN. you will connect via IAX or SIP and register with a provider over the internet - calls will leave your facility via IP and terminate to the PSTN at your providers location. it’s much cheaper to do it this way, and you can still get a PSTN number ported so that standard phones can still call you…i’m not an expert at this end of things, but i plan on utilizing an ITSP for my home PBX when i finally get around to building it.

good luck.

Thanks for the info, do you know any ITSP’s that I can use for business purpose so I can charge them the rates I want and give the ITSP a standard rate. I would really appriciate that. Or What do I need to become an ITSP?

Sorry Guys I have one more question, I understand now that I need a ITSP to make long distance and local outbound calls to PSTN but If I use my standard POTS at home I can call within canada for free. So my question over here is that is it possible that I can use Asterisk and the FXO card to connect to my standard POTS and make local calls in Canada but at the same time can Asterisk connect to an ITSP to make long distance calls?

Instead of using Phone Lines, you can use the internet…

There are many Telco’s over the internet that you can use which I find to be cheaper, so you would have to pay them and for the internet bandwidth. is the one i use

i don’t know about a business level one, but here is a good place to start: … s+Business

and yes, you can use both an ITSP and PSTN line concurrently - you’d have to set your dialplan to allow the system to choose which provider to dial out on, based on what number you dial out. but it would probably be cheaper to go with just an ITSP - the per minute rates are incredibly low for most of the major players…

Hey guys thanks so much, the help here is incredible i am ready to start now. If any problems and updates I will keep you guys posting.

Looking for a big project here in canda…

Hey guys one more question, I wanted to know if you guys will recommend removing my SIP proxy server and allow my SIP phones connect directly to my PBX, in that case I can do all my config on Asterisk. Will this be a good idea or is there a benefit using SIP proxy server and PBX together. Just need some recommendation here.

for your size installation, i would say that a proxy server isn’t going to offer the same benefits as it would for a larger system.

i don’t know much about proxys, but the little bit of playing i did with OpenSER didn’t provide us with any additional benefits. i know it COULD, if i knew more about it.

me personally, i’d focus on getting asterisk up and running by itself. once you’ve mastered that, and have everything running smoothly, you could build a test lab and throw a proxy server into the mix. then you could tinker and figure out all of the cool stuff you can do. just do me a favor - when you do find all the cool stuff, let me know!

Hey whoiswe,

thanks for ur reply man, i will let u know when i m done. Just another quick question, what linux distribution u r using ur asterisk on…