dependability

The quality of service models of telecommunication networks was considered. The features of providing of quality of service in the telephone and computer networks was explored. On the basis of this research it sets, that the metropolitan telephone networks are characterized by a higher accuracy, dependability and security by comparison to the computer local area networks. Substantial advantage of computer local area networks above the metropolitan telephone networks is providing a higher speed of the user information transfer, although defect there is an instability of this speed.