The most popular is wholesale business, because it is the simplest way to earn money by trading VoIP traffic at wholesale. Wholesaler profits are generated from difference of buying prices and selling prices. Thus, the main target is to find the cheapest price for some route and to sell it more expensive as you can! A VoIP wholesaler, which buys traffic from other wholesaler and then sells them to other wholesaler, is named as Simple Wholesaler.
The start-point of a route for traffic is named as Origination Point. As usual, originator is a retailer-company, which sells prepaid-cards, has call shops, offers IP-Phone services etc. The end-point of a route for traffic is named as Termination Point. And a terminator is not only retailer, but it could be also a wholesaler. Thus, a wholesaler, which makes a termination point, is named as Termination Wholesaler.
In order to terminate traffic wholesaler needs to have an entrance to some PSTN or cellular network. This entrance is called as an access channel to a public network and forms by one or several gateways.