Sun Microsystems SunFDDI/P 1.0 User Manual page 171

TRT
TTRT
(Token Rotation Timer). A timer in the FDDI MAC protocol that measures the
time between receipt of tokens. It expires when it reaches a value that exceeds
the Target Token Rotation Time (TTRT).
(Target Token Rotation Time). A parameter in the FDDI MAC protocol that is
negotiated by all of the stations on a ring at the time a ring is brought up. FDDI
uses the TTRT in conjunction with the TRT and THT to allocate bandwidth to
individual stations on the ring. The FDDI MAC protocol guarantees that the
worst-case delay a token will experience while circulating the ring will never
exceed twice the negotiated TTRT.
Glossary 145