Both dial-up and leased-line links involve two peers that are connected by a communications medium. The next table summarizes the differences between the link types.
Leased Line |
Dial-up Line |
---|---|
Always connected, unless a system administrator or power failure takes the leased-line down. |
Initiated on demand, when a user tries to call a remote peer. |
Uses synchronous and asynchronous communications. For asynchronous communications, a long-haul modem is often used. |
Uses asynchronous communications. |
Rented from a provider. |
Uses existing telephone lines. |
Requires synchronous units. |
Uses less costly modems. |
Requires synchronous ports, which are common on most SPARC systems. However, synchronous ports are not common on x86 systems and newer SPARC systems. |
Uses standard serial interfaces that are included on most computers. |