Hold baggage allowance is regulated by Airlines basing on ticket class. Some Airlines apply international practice while the other have their own standards. So when buying air tickets, passengers should  check carefully to understand  these rules.
For hold baggage allowance: According to the standard, category and type of each airline tickets.

For cabin baggage: Each piece will not exceed 7 kg and with total of three dimensions not exceeding 115cm ( corresponding to 56 x 36 x 23 cm  or 22 x 14 x 9 inches).

Where the baggage exceeds the quantity, weight, size according to the above provisions, the airline may refuse to accept it as cabin baggage and passenger will be required to process it for hold baggage.