[asterisk-biz] Need reliable provider for Canada, USA and Europe DIDs

My current provider for Canadian DIDs is excellent, but charges only on per minute basis both for incoming and outbound minutes, due to which its hard for me to resell my service to those customers whose usage is more than 1000 minutes a month. It becomes expensive for them. They start referring to those who charge only pennies per month. Even cell phone usage for unlimited incoming these days is cheap.

Now I am trying to expand my business and I already have request for London and Toronto DIDs, plus I expect to have need for USA DIDs in near future. So I need to be hooked up to a good DID provider for these areas, who can give better rates than what I have right now.

I also want to have option to setup multiple incoming and outbound channels on same DIDs. Some customers need only 2 channels, whereas others need 6. Not all the providers provide this option.

Any ideas, suggestions, recommendations from those who are already in this business. Should I get virtual PRI, and how it works? I googled, and visited a few providers. But I don't know yet whom to go with, who will not disappear like Allo, or will give me hard time like some other smaller companies. From their websites, they all look good.

Thanks,
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Zeeshan A Zakaria