RPL Parent Device Route Saturation Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In RPL storing mode networks, parent devices can become saturated due to memory constraints, limiting the scalability of the network as they run out of free memory space for storing routes, especially in grandparent devices that need to store routes of their children acting as storing-mode parents.
Innovation Solution
A method where child network devices detect saturation in parent devices by receiving saturation information in DIO messages and proactively manage route storage by moving at least a portion of stored routes to an alternate unsaturated parent device, dynamically adjusting storage to avoid saturation and optimize memory usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a RPL storing mode parent network device stores routes of all child network devices, then routing information completeness is improved, but memory saturation occurs limiting network scalability
Solution Approach 1:
The patent segments the routing information storage function by introducing a distinction between storing-mode and non-storing-mode child network devices. Storing-mode children contribute to routing information while non-storing-mode children do not require their routes to be stored in the parent, effectively dividing the storage burden and preventing memory saturation in parent devices.
2Loss of information
If grandparent devices store routes of their children that are storing-mode parents, then routing information completeness is improved, but memory saturation occurs more severely
Solution Approach 1:
The patent applies segmentation at multiple levels of the network hierarchy. Grandparent devices only store routes from non-storing-mode children, while storing-mode children's routes are handled by their respective parents. This multi-level segmentation prevents cumulative memory saturation that would otherwise occur when grandparents store all descendant routes.
Solution Approach 2:
The patent extracts the routing storage function from higher-level devices (grandparents) for storing-mode children. Instead of grandparents storing all child routes including those of storing-mode parents, the storage responsibility is extracted and assigned only to the immediate parents of non-storing-mode children, reducing the memory burden on grandparents.
3Device complexity
If all child network devices attach to the same parent, then network topology simplicity is improved, but parent device memory saturation occurs
Solution Approach 1:
The patent applies local quality by assigning different operational modes to different child network devices based on their capabilities and requirements. Non-storing-mode children attach to parents that can handle their routing information, while storing-mode children are configured to have their parents not store their routes. This local differentiation allows higher device density per parent without causing memory saturation.
Data Source
AI summary
In one embodiment, a method comprises attaching, by a constrained network device in a data network, to a first parent network device in a tree-based storing mode topology in response to receiving a first advertisement message generated by the first parent network device; outputting to the first parent network device a plurality of routes stored in the constrained network device, the routes identifying destinations reachable via the constrained network device; determining, by the constrained network device, that the first parent network device is encountering saturation of stored routes based on the constrained network device receiving a second advertisement message from the first parent network device; and eliminating, by the constrained network device, the saturation encountered by the first parent network device based on moving at least a portion of the routes from the first parent network device to a second parent network device in the tree-based storing mode topology.