Inter-city Cab Service from downtown Ottawa

Hello,

I recently moved to Ottawa from Vancouver and don't drive/ own a car yet, I just turned 19. I may have to travel out of the city - Brockville, Perth, Cornwall to see family for instance.

Are there reliable, inter-city cab service that you would recommend?

Edit: Something that I can book-out for about half a day - and have them bring me back to Ottawa