Dunno about Canada, but in the US a fixed-rate mortgage is, well, fixed. My rate will never change, and thus my monthly payment will remain exactly the same for the 30-year life of the loan.
I'm not sure about other Commonwealth countries, but Canada definitely does not have this option. Our mortgages have a specific mortgage rate term (usually 3-5 years), separate from the life-time of the mortgage (usually 20-30 years; the 35 was/will be no longer be available). This means that interest rate fluctuations are more devastating when they rise for those who put little to no money down on their expensive housing purchases in Canada recently.
Amortization length of a mortgage can be up to 35 years for residential mortgages. 35 year amortizations were only eliminated for CMHC/insured mortgages.
I would contend that the system is more stable when borrowers are forced to consider the consequences of future interest rate increases.