2.An AMP/SMP MAC frame with the A/C bit set B′0′ is seen. This indicates that there is only one station attached to this port and the address of that
station is one which is seen in the AMP/SMP MAC frame with the A/C bit set to B′0′. In this case, the AMP/SMP MAC frame sent by the upstream station
is copied by the station attached to this port. Then the station attached to
this port has issued its own AMP/SMP MAC frame which will pass this Ring Monitor with the A/C bit set to B′0′. The source address in this AMP/SMP
MAC frame is the address of the station attached to this port.
3.Several AMP/SMP MAC frames with the A/C bit set to B′1′ are seen followed by an AMP/SMP MAC frame with the A/C bit set B′0′.
This indicates that there are several stations attached to this port via a
In this case, the AMP/SMP MAC frame sent by the upstream station is copied by the station attached to the first port of the
Note
A
The AMP/SMP issued by the last (or the only) station on each port will pass the Ring Monitor function on that port and will immediately be seen by the Ring Monitor function on the next port downstream from this port. As soon as the Ring Monitor on the downstream port sees this AMP/SMP MAC frame with the A/C bit set to B′0′, it moves downstream of its associated port and will then signal the Ring Monitor on the upstream port which currently is situated downstream of its associated port to move to the upstream of its associated port to prepare for the next round of neighbor notification as well as assisting the Recovery ASIC with the beacon recovery process.
The above procedure will be repeated on all the ports helping the Recovery ASIC to build an accurate
