System and method for link-state based proxy flooding of messages in a network

1. A method of disseminating information in a communication network including a plurality of nodes, the method comprising the steps of:

(a) receiving, in a node, a packet including link-state advertisements (LSAs) from the communication network, at least one LSA including a flooding status field;

(b) determining, in the node, a type of LSA received based on the flooding status field; and

(c) re-flooding the packet, from the node, onto the communication network, based on the type of LSA determined in step (b);

wherein the node includes a re-flood timer, and

step (c) includes waiting a first interval of time for the re-flood timer to expire, and re-flooding the packet, from the node, onto the communication network after waiting the first interval of time for the re-flood timer to expire; and

step (a) includes receiving a sub-field in the flooding status field indicating an urgency level for the at least one LSA, and

step (c) includes setting, by the node, the re-flood timer to expire after a second interval of time based on the indicated urgency level, and

waiting, by the node, for the re-flood timer to expire after the second interval of time, and then re-flooding the packet from the node onto the communication network, the second interval of time being different from the first interval of time.

2. The method of claim 1 wherein step (a) includes receiving a bit in the flooding status field indicating the at least one LSA is intended for distribution to the entire communication network, and

step (c) includes re-flooding, from the node, the at least one LSA onto the communication network in response to the bit in the flooding status field.

3. The method of claim 1 wherein step (a) includes receiving a bit in the flooding status field indicating the at least one LSA is intended for distribution to other nodes in the communication network located within a predetermined range of the node, and

step (c) includes preventing re-flooding of the at least one LSA, from the node, if the other nodes in the communication network are located outside of the predetermined range.

4. The method of claim 3 wherein step (a) includes receiving a sub-field in the flooding status field indicating a time-to-live (TTL) value, and

step (c) includes re-flooding the at least one LSA, from the node, onto the communication network, if the received TTL value is greater than a value of one, and

preventing re-flooding of the at least one LSA if the received TTL value is equal to a value of zero.

5. The method of claim 4 wherein the node receiving the at least one LSA is a flooding proxy node, and

the other nodes of the communication network include at least one flooding group member node and another flooding proxy node.

6. The method of claim 1 in which the node includes an acknowledge timeout timer, and the following additional steps:

(d) setting an interval of time for the acknowledge timeout timer to expire based on an urgency level for the at least one LSA;

(e) waiting the interval of time for reception of an acknowledgement packet from another node in the communication network, after re-flooding the packet in step (c); and

(f) again re-flooding the packet, from the node, onto the communication network, if the acknowledgement packet from the other node is not received during the interval of time.

7. The method of claim 1 wherein

the urgency level includes a value indicating that the at least one LSA requires an interval of time sufficient for processing the at least one LSA, the value effective in slowing re-flooding of the at least one LSA in the network.

8. In a node disseminating information by transmitting link state advertisements (LSAs) to other nodes in a network, the node comprising

a transmitter for transmitting LSAs to other nodes in the network,

a processor for assembling at least one LSA and providing the LSA to the transmitter for transmission onto the network, and

the processor including an engine for generating a flooding status field in the at least one LSA,

the flooding status field including an urgency level having a value indicating that the at least one LSA requires an interval of time sufficient for processing the at least one LSA, the value effective in slowing re-flooding of the at least one LSA in the network.

9. The node of claim 8 wherein the flooding status field includes a reliable flooding flag indicating an acknowledgment is required by another node after the LSA is transmitted onto the network, and

a normal flooding flag indicating that an acknowledgement is not required by the other node after the LSA is transmitted onto the network.

10. The node of claim 9 further including

an acknowledgement timeout timer coupled to the engine for measuring an interval of time, and

a receiver coupled to the processor for receiving acknowledgement packets from other nodes in the network in response to the at least one LSA transmitted by the transmitter,

wherein after the interval of time expires in the acknowledgement timeout timer and an acknowledgement packet is not received in the receiver, the engine assembles another LSA for re-transmission onto the network.

11. The node of claim 10 in which the node is a flooding proxy node of a first cluster of nodes in the network, and

the other nodes are at least one flooding group member node of the first cluster of nodes, and at least one flooding proxy node of a second cluster of nodes in the network.

12. The node of claim 8 wherein a TTL value is received from another external node, and the processor reduces the TTL value by a value of one, and

if the TTL value is less than the value of one, after having reduced the TTL value, the processor prevents the LSA from being provided to the transmitter for transmission onto the network.

13. The node of claim 8 wherein

the processor sets a TTL value to any hop-count value corresponding to a desired range the LSA is to be flooded, if the node originates the LSA, and

the hop-count value set by the originating node is permitted to be different from another hop-count value set by another originating node in the network.