Dynamic Standby Controller Assignment for Access Point Redundancy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In computing networks, when a controller fails, some access points (APs) lose their standby controller assignments, leading to potential radio frequency (RF) gaps and network connectivity disruptions for client devices, as the operational capacity of remaining controllers is exhausted, limiting full redundancy and causing APs to rebootstrap, which results in significant downtime.
Innovation Solution
The network controller reassigns standby controller assignments among APs to prevent RF gaps by determining the size of potential RF gaps and reallocating standby controller roles, ensuring that APs can maintain connectivity even if another controller fails, thereby preventing rebootstrap events and ensuring continuous network access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standby controller assignments are not reassigned after a controller failure, then the system structure remains simple, but RF gaps occur and network connectivity is disrupted
Solution Approach 1:
The controller assignment system transitions from a static configuration to a dynamic one where standby controller assignments are automatically reassigned when controller failures occur. The network controller continuously monitors controller status and dynamically updates AP assignments to maintain optimal redundancy coverage, preventing RF gaps while adapting to changing system conditions.
Solution Approach 2:
The system implements feedback mechanisms where the network controller monitors controller failures and automatically triggers reassignment of standby controller assignments to APs. This closed-loop feedback ensures that redundancy is maintained by detecting failures and responding with appropriate reconfiguration actions to prevent connectivity disruptions.
2Reliability
If standby controller assignments are reassigned dynamically, then redundancy is maintained and connectivity is preserved, but system complexity and reassignment overhead increase
Solution Approach 1:
The network controller performs self-service by automatically detecting controller failures and reassigning standby controller assignments without external intervention. The system monitors its own health status and autonomously executes reassignment operations to maintain redundancy, reducing the need for manual configuration while preserving reliability.
3Productivity
If APs rebootstrap after controller failure, then controller capacity is reset, but significant downtime occurs and connectivity is lost
Solution Approach 1:
The system performs preliminary actions by pre-establishing standby controller assignments before failures occur. When a controller fails, APs already have designated standby controllers ready to take over immediately, eliminating the need for time-consuming rebootstrap operations and preventing connectivity loss while controller capacity is recovered.
Solution Approach 2:
The network controller prepares cushioning measures by maintaining standby controller assignments as a buffer against potential failures. This prior cushioning ensures that when controller failures occur, APs can seamlessly transition to standby controllers without experiencing downtime or connectivity disruption.
4Productivity
If operational capacity of remaining controllers is exhausted, then load is distributed, but full redundancy cannot be maintained and APs lose standby assignments
Solution Approach 1:
The system dynamically adjusts standby controller assignments based on the operational capacity of remaining controllers. When load distribution causes capacity exhaustion, the network controller identifies and reassigns standby roles to APs that can accommodate them, maintaining full redundancy coverage while adapting to the current load distribution state.
Data Source
AI summary
Example implementations relate to standby controllers for access points (APs). A network controller may comprise a processing resource; and a memory resource storing machine-readable instructions to cause the processing resource to: determine, in response to a first controller in a controller cluster failing, whether a first AP managed by a first controller has been assigned to a standby controller; determine, in response to the first AP managed by the first controller not having a standby controller assigned, a radio frequency (RF) gap as a result of a different controller failing; and based on the size of the RF gap, assign the second controller as a standby controller for the first AP.