Distributed control technique for RPL topology

• US 8,392,541 B2
• Filed: 05/27/2011
• Issued: 03/05/2013
• Est. Priority Date: 04/01/2011
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Agarwal, Navneet, Vasseur, Jean-Philippe
• Primary Examiner(s): DINH, KHANH Q
• Application Number:
  US13/117,276
• Publication Number:
  US 20120254338A1
• Time in Patent Office: 648 Days
• Field of Search: 709/220, 709/224, 709/228, 370/252, 370/389
• US Class Current: 709/220
• CPC Class Codes: H04L 45/14 Routing performance; Theoretical aspects
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 40/32 for defining a routing cluster membership

Abstract

In one embodiment, a distributed control technique may enable management of a monolithic routing topology of nodes in a computer network by apportioning the monolithic routing topology into a plurality of regional routing topology domains, each represented by a directed acyclic graph (DAG). The regional topology domains may include a super topology domain that is established as a super-DAG of intermediate nodes interconnected with leaf nodes and rooted by a master node of the computer network. The regional topology domains may further include at least one local topology domain that is established as a local-DAG of intermediate nodes interconnected with leaf nodes and rooted by a local root node of the computer network. Notably, a super node of the computer network may be configured to participate in both the super topology domain as an intermediate node of the super-DAG and the local topology domain as the local root node of the local-DAG.

Claims

1. A method, comprising:

apportioning a monolithic routing topology of nodes in a computer network into a plurality of regional topology domains, each represented by a directed acyclic graph (DAG);

establishing a super topology domain of the regional topology domains as a super-DAG of intermediate nodes interconnected with leaf nodes and rooted by a master node of the computer network;

establishing at least one local topology domain of the regional topology domains as a local-DAG of intermediate nodes interconnected with leaf nodes and rooted by a local root node of the computer network;

configuring a super node of the computer network to participate in both the super topology domain as an intermediate node of the super-DAG and the local topology domain as the local root node of the local-DAG;

creating a topology-connecting fabric between the super node and master node to interconnect the local topology domain with the super topology domain; and

utilizing the topology-connecting fabric to enable the master node to globally manage the monolithic routing topology including the plurality of regional topology domains.

2. The method as in claim 1, wherein utilizing the topology-connecting fabric comprises:

enabling the master node to directly control the super topology domain; and

, distributing control of the local topology domain from the master node to the super node.

3. The method as in claim 1, wherein creating the topology-connecting fabric comprises:

establishing a hierarchy of topology domains.

4. The method as in claim 1, wherein creating the topology-connecting fabric comprises:

communicating between the super node and the master node through exchange of unicast control messages.

5. The method as in claim 4, wherein the unicast control messages includes a unicast Destination Advertisement Object (DAO) message.

6. The method as in claim 5, wherein communicating comprises:

employing the unicast DAO message to communicate address information from the super node to the master node.

7. The method as in claim 6 wherein the super node has a globally routable address and wherein employing comprises:

inserting the globally routable address in a target field of the unicast DAO message.

8. The method as in claim 7, wherein employing further comprises:

providing an indication to the intermediate nodes to ignore the target field and relay the unicast DAO message to the master node.

9. The method as in claim 8, wherein the indication is a flag bit of the unicast DAO message.

10. The method as in claim 7, further comprising:

processing the target field of the unicast DAO message to build a master DAG database at the master node.

11. The method as in claim 5, wherein communicating comprises:

employing the unicast DAO message to communicate configuration information from the super node to the master node.

12. The method as in claim 11, wherein the configuration information includes parameters and monitoring statistics, and wherein employing comprises:

changing the parameters in a local DAG database; and

reporting the changed parameters to the master node using a configuration field of the unicast DAO message.

13. The method as in claim 12, further comprising:

updating a master DAG database in response to the changed parameters; and

monitoring a state of the local topology domain using the updated master DAG database.

14. The method as in claim 4, wherein the unicast control messages includes a unicast DAG Information Object (DIO) message.

15. The method as in claim 14, wherein communicating comprises:

sending the unicast DIO message to the super node to trigger global repair in the local topology domain.

16. The method as in claim 15, wherein sending comprises:

directing the unicast DIO message from the master node to the super node by loading a destination address of the super node into a destination field of the unicast DIO message.

17. An apparatus, comprising:

one or more network interfaces connected to a computer network;

a processor coupled to the network interfaces and adapted to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

apportion a monolithic routing topology of nodes in the computer network into a plurality of regional topology domains, each represented by a directed acyclic graph (DAG);

establish a super topology domain of the regional topology domains as a super-DAG of intermediate nodes interconnected with leaf nodes and rooted by a master node of the computer network;

establish at least one local topology domain of the regional topology domains as a local-DAG of intermediate nodes interconnected with leaf nodes and rooted by a local root node of the computer network;

configure a super node of the computer network to participate in both the super topology domain as an intermediate node of the super-DAG and the local topology domain as the local root node of the local-DAG;

create a topology-connecting fabric between the super node and master node to interconnect the local topology domain with the super topology domain; and

utilize the topology-connecting fabric to enable the master node to globally manage the monolithic routing topology including the plurality of regional topology domains.

18. The apparatus as in claim 17, wherein the process when executed is further operable to:

enable the master node to directly control the super topology domain; and

, distribute control of the local topology domain from the master node to the super node.

19. The apparatus as in claim 17, wherein the process when executed is further operable to:

establish a hierarchy of topology domains.

20. One or more non-transitory computer readable storage media encoded with software comprising computer executable instructions and when the software is executed operable to:

apportion a monolithic routing topology of nodes in a computer network into a plurality of regional topology domains, each represented by a directed acyclic graph (DAG);

establish a super topology domain of the regional topology domains as a super-DAG of intermediate nodes interconnected with leaf nodes and rooted by a master node of the computer network;

establish a local topology domain of the regional topology domains as a local-DAG of intermediate nodes interconnected with leaf nodes and rooted by a local root node of the computer network;

configure a super node of the computer network to participate in both the super topology domain as an intermediate node of the super-DAG and the local topology domain as the local root node of the local-DAG;

create a topology-connecting fabric between the super node and master node to interconnect the local topology domain with the super topology domain; and

utilize the topology-connecting fabric to enable the master node to globally manage the monolithic routing topology including the plurality of regional topology domains.