Complete Protocol dictionary, glossary and reference

TUD: Trunk up-down

Trunk up-down(TUD) is a protocol used in ATM networks that monitors trunks and detects when one goes down or comes up. ATM switches send regular test messages from each trunk port to test trunk line quality. If a trunk misses a given number of these messages, TUD declares the trunk down. When a trunk comes back up, TUD recognizes that the trunk is up, declares the trunk up, and returns it to service.

Standard Organization

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