I am looking to start a VOIP company and i know what i need to do the voip side but iv found it very hard to find any information on how to get my customers to be able to call people on regular lan lines. I know it goes through a pstn gateway but how do i get a connection to these gateways (as in who do i talk to)? Can i get my own pstn gateway and reduce the cost that way? What is the cost of a pstn gateway. Any information is very appreciated.

Thank you.