These fields contain individual 48-bit MAC address as specified in IEEE.
The flood indication is used to avoid persistent flooding in bridged applications
of RPR. Flooded frames are forwarded to the client bridge entity regardless of their
destination address.
The passed source bit is used by wrapping systems (along with other fields) to prevent
frame misorder and duplication by preventing the frame from being wrapped
more than two times by the wrapping network. It is set to 0 when a frame is first
transmitted by a station and set to 1 when a wrapped frame (i.e., a frame traveling on
the secondary ringlet) passes the source station.
A frame with a bad HEC is discarded since the header information is corrupted and
no reliable delivery of the frame can be assured. A data frame with a bad FCS is not discarded
on transit, but it is stomped by the first station detecting a bad FCS to avoid multiple
counting of the same errored frame in different stations along the transit path.
A station receiving a frame with a corrupted FCS may decide to accept it or discard
it, according to a configuration parameter. Accepting a frame with corrupted FCS may
be of value for services such as TDM pseudo wire emulation, where some bit errors may
be tolerated.
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