Metropolitan Area Networks (MANs) are networks that connect LANs together within a city.
The main criterion for a MAN is that the connection between LANs is through a local exchange carrier generally the local phone company.
The protocols that are used for MANs are quite different from those used for LANs.
Examples of MAN protocols are:
Asynchronous Transfer Mode (ATM).
ISDN (Integrated Services Digital Network) PRI and BRI.
XDSL (many different types of Digital Subscriber Lines).