11. There is no number pooling and rate centres are typically not amalgamated when the corresponding municipalities disappear. 12. Number portability usually has geographic limitations, such as an a competitor within the same rate centre . 13. Many of Canada's larger cities are split between multiple rate centres that have never been amalgamated. 14. It would also have been extremely difficult to split Toronto, since it is a single rate centre . 15. Every competing carrier is issued blocks of 10, 000 numbers for every rate centre where it offers service. 16. Much like FX service rates depend on the distance between rate centres , FCO service prices depend on the distance between exchanges. 17. Elsa survives as a rate centre only because it was eclipsed by relatively stable Keno, which is served by the same exchange. 18. A similar " FCO " service provided no difference in local calling area ( the distant exchange is in the same rate centre ). 19. Each CLEC is assigned blocks of 10, 000 numbers for every rate centre where it plans to offer service, no matter how small. 20. While most regions do not need that many phone numbers, once a prefix is assigned to a rate centre , it cannot be allocated elsewhere.
