Voip calls to gsm network

I am unable to make a call to cell phone or international number.While usually it is said that asterisk does not need extra hardware and when we study about making calls to gsm network, gateways are considered as remedy but if someone do not have gateways what will he do.I also know that asterisk do support gsm coz it has codecs

How are you trying to make the calls? You mean the calls are failing, or that you want to know the best/cheapest way to call mobiles and international numbers?

No what im trying to say is that ive a lan setup and i want to make calls to gsm network or mobile phone as we have option in softphone but it dont work which i know is not possible without gateways or cards being installed but i dont have resources and i want to make it without gateways or any additional hardware. I have asterisk pbx setup.Isnt there any alternative to all this, because it is usually said on official sites of asterisk that it do not need extra hardware.

I’m not sure I understand what you are trying to do, but if you are trying to call an external number, i.e. outside your network, you will need a connection to the PSTN. You can either (a) use a fxo module to connect your Asterisk box to a POTS line, or (b) open an account with a DID service provider, see http://www.voip-info.org/wiki/index.php?page=DID+service+providers (although this information is not necessarily up to date.)

Ian

yes u r now following me, u r right but i cannot afford cards or gateways.What im saying is that isnt there any alternative like software which can replace gateways or cards.Plz if u can help.

Only (b) above.