User Manual

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Users Manual of XGS-6350-24X4C
block its secondary port. At the same time, the master node will periodically transmit the Hello packets from its
primary port. These hello packets will pass through the transit node in sequence and finally return to the
master node from its secondary port. The ring in complete state is shown in the following figure. The major
ring and two sub rings are all in complete state. The hello packet of the major ring is only broadcast in the
major ring, while the hello packet of the sub ring can be transparently transmitted through the major ring, then
return to the sub ring, and finally get the secondary port of the master node on the sub ring.
Figure 11: Complete state
27.3.2.1 Link-Down
The link-down state of the ring is decided by the polling mechanism, the notification of the link state change
and the channel status checkup mechanism of the sub-ring protocol packet. Surely the link-down state of the
ring is also advocated as to only one ring. When some link in the ring is in link-down state, the ring changes
from the compete state to the troubled state, that is, the link-down state.
If link-down occurs on a link, the polling mechanism and the link status change notification mechanism will
both function. The transit node, on which link-down occurs, will transmit the link-down packet to the master
node through the Up port at its other side; at the same time, the polling mechanism will monitor and change
promptly the state of the ring through Fail Time. When a trouble occurs on the sub-ring protocol channel, the
trouble will be handled by the channel status checkup mechanism of the sub-ring protocol packet on the major
ring. As shown in the following figure, the trouble notification message on the link of the major ring and on the
common link is only transmitted on the major ring and finally transmitted to the master node; the trouble
notification message on the link of sub ring 2 will be transmitted to the master node of the sub ring, which can
be transparently transmitted through the major ring.