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Glossary
V.54: The ITU-T standard for local and remote loopback tests in modems, DCEs and DTEs. The four basic tests are:
• local digital loopback (tests DTE send and receive circuits),
• local analog loopback (tests local modem operation),
• remote analog loopback (tests comm link to the remote modem), and
• remote digital loopback (tests remote modem operation).
Virtual Circuit: A logical connection. Used in packet switching wherein a logical connection is established between two devices at the
start of transmission. All information packets follow the same route and arrive in sequence (but do not necessarily carry a complete
address).