Cabletron Systems Element Manager 2.1, Руководство пользователя

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FDDI Management
5-4 Configuration
condition causes ring initialization to fail after the claim
and beacon recovery process. Like Non-Op-Dup, this
state will not occur unless you are using
locally-administered addresses.
Directed The beacon process did not complete within 7 seconds.
The selected SMT has directed the controlled MAC to
send beacon frames to notify the other stations that a
serious problem exists on the ring, and a Trace state is
soon to follow.
Trace A problem exists on the ring which could not be
corrected during the beaconing process, and a Trace has
been initiated. During a Trace (or Path Test), the SMT
sends a signal that forces its nearest upstream neighbor
to remove from the ring and conduct a self-test. If the
ring does not recover, each subsequent upstream station
will be forced to remove from the ring and conduct
self-tests until the problem has been corrected. While the
test is being conducted, ring management re-enters the
isolated state.
SMT Version
Displays the version number of the Station Management (SMT) entity. SMT
provides the system management services for the FDDI protocols, including
connection management, node conÞguration, error recovery, and management
frame encoding. SMT frames have a version ID Þeld that identiÞes the structure
of the SMT frame Info Þeld. The version number is included in the SMT frame so
that a receiving station can determine whether or not its SMT version is able to
communicate with the SMT version of another station. Knowing the version
number allows the stations to handle version mismatches. Each FDDI station
supports a range of SMT versions. The supported version range is identiÞed
within the ietf-fddi MIB by two smtTable attributes: snmpFddiSMTLoVersionId
and snmpFddiSMTHiVersionId. If a received frame is not within the supported
version range, the frame is discarded.
T-Req. (Requested Target Token Rotation Time)
The token rotation time bid made by the selected SMT entity during ring
initialization. Each station detecting that the ring must be initialized begins a
claim token process and issues a stream of Claim Frames, which negotiate the
value assigned to the Target Token Rotation Time (TTRT). The information Þeld of
these frames contains the issuing stationÕs bid for the value of TTRT. Each
claiming station inspects incoming Claim frames (from other issuing stations) and
either continues its own bid (and removes the competing Claim Frame from the
ring) or defers (halts transmission of its own bid and repeats the competing bid)
according to the following hierarchy of arbitration:
¥ A Claim Frame with the lowest TTRT bid has precedence.
¥ If the values of TTRT are equal, the frame with the longest source address
(48 vs. 16 bits) has precedence.