BRAS Address Distribution via Notification Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In dual-server hot backup scenarios for Broadband Remote Access Servers (BRAS), address collisions occur when both backup BRAS devices simultaneously distribute the same address to users without proper synchronization, leading to service disruptions and quality issues.
Innovation Solution
The method involves configuring address distribution rules for each BRAS device to manage addresses in a shared pool using forward and reverse sequence distribution modes, with notification messages sent to backup devices upon address allocation and release, ensuring unique address allocation and preventing collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If both BRAS devices access the shared address pool simultaneously without coordination, then address availability is improved, but address collisions occur
Solution Approach 1:
The patent applies preliminary action by having the active BRAS device send a notification message to the standby BRAS device before allocating an address from the shared pool. This advance notification allows the standby device to mark the address as unavailable in its local record, preventing the collision from occurring in the first place. The key phrase is 'before the BRAS synchronizes the address information of the user to a backup device, the backup device also has the users getting online and distributes the same address', which the invention prevents through proactive notification.
Solution Approach 2:
The patent implements feedback by establishing a notification mechanism where the active BRAS device informs the standby device of address allocations. The standby device provides feedback by maintaining a local record of unavailable addresses based on these notifications. This feedback loop ensures that when the standby device needs to allocate addresses, it can check its local record and avoid distributing addresses that are currently in use by the active device.
2Reliability
If address synchronization is performed in real-time, then address collision is prevented, but system complexity increases
Solution Approach 1:
The patent applies the taking out principle by extracting the synchronization function from a complex real-time bidirectional synchronization mechanism and simplifying it to a unidirectional notification system. Instead of both devices continuously monitoring and updating each other, only the active device needs to send notifications to the standby device. This reduces the complexity of the synchronization mechanism while maintaining address allocation uniqueness.
Solution Approach 2:
The patent applies local quality by allowing each BRAS device to maintain its own local record of address availability with different characteristics. The active device has full access to the shared address pool, while the standby device has a local record of unavailable addresses derived from notifications. This local differentiation simplifies the overall system compared to requiring both devices to maintain identical real-time views of the address pool.
3Reliability
If the standby device checks address availability in real-time, then address collision is avoided, but response time increases
Solution Approach 1:
The patent applies preliminary action by having the standby device pre-mark addresses as unavailable when it receives notification messages from the active device, before the active device actually completes its allocation process. This way, when the standby device needs to allocate an address, it can immediately check its local record without needing to wait for or coordinate with the active device, significantly reducing the address distribution time while still preventing collisions.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An address distribution method is disclosed by the present invention, in which two Broadband Remote Access Servers (BRAS) which are mutually backup devices respectively occupy part of the address resources in a shared address pool, and the method includes: when detecting a user online, a BRAS selecting an address from the corresponding part of address resources in the shared address pool and distributing the address to the user; and the BRAS sending a notification message to the backup device, and informing the backup device of the address occupied by the user. A BRAS and an address distribution system is further disclosed by the present invention, and the problem of address collision generated when a pair of BRASs which are mutually backup devices distribute the addresses to their respective user in the dual-server hot backup scenario is solved by the method, device and system of the present invention.