Mrpp Protocol Packet Types - Planet XGS3-42000R User Manual

3. nodes
Each switch is named after a node on Ethernet. The node has some types:
Primary node: each ring has a primary node, it is main node to detect and defend.
Trans fer node: except for primary node, other nodes are trans fer nodes on each ring.
The node role is determined by user configuration. As shown above, Switch A is primary node of Ring 1,
Switch B. Switch C; Switch D and Switch E are trans fer nodes of Ring 1.
4. Primary port and secondary port
The primary node and transfer node have two ports connecting to Ethernet separately, one is primary port,
and another is secondary port. The role of port is determined by user configuration.
Primary port and secondary port of primary node
The primary port of primary node is used to send ring health examine packet (hello), the secondary port is
used to receive Hello packet sending from primary node. When the Ethernet is in health state, the
secondary port of primary node blocks other data in logical and only MRPP packet can pass. When the
Ethernet is in break state, the secondary port of primary node releases block state, and forwards dat a
packets.
There are no difference on function bet ween Primary port and secondary port of transfer node.
The role of port is determined by us er configuration. As shown in above, S witch A E1 is primary port, E2 is
secondary port.
5. Timer
The two timers are used when the primary node sends and receives MRPP prot ocol packet: Hello timer and
Fail Timer.
Hello timer: define timer of time interval of health examine packet sending by primary node primary port.
Fail timer: define timer of overtime interval of health examine packet receiving by primary node primary port.
The value of Fail timer must be more than or equal to the 3 times of value of Hello timer.

60.1.2 MRPP Protocol Packet Types

Packet Type
Hello packet (Health examine packet) Hello
LINK-DOWN (link Down event packet)
LINK-DOWN-FLUS H_FDB packet
LINK-UP-FLUS H_FDB packet
The primary port of primary node evokes to detect ring, if the
secondary port of primary node can receive Hello packet in
configured overtime, so the ring is normal.
After transfer node detects Down event on port, immediately
sends LINK-DOWN packet to primary node, and inform primary
node ring to fail.
After primary node detects ring failure or receives LINK-DOW N
packet, open blocked secondary port, and then us es two ports
to send the packet, to inform each transfer node to refresh own
MAC address.
After primary detects ring failure to restore normal, and uses
packet from primary port, and informs each transfer node to
refres h own MAC address.
60-2
Explanation