MME Service Redundancy via DNS-Based Backup Selection
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Solution Overview
Problem
The existing redundancy solutions in LTE networks for MMEs have a relatively poor redundancy effect, leading to service failures and HSS congestion when an MME becomes faulty, especially during VoLTE services, due to the lack of efficient user information transfer and load balancing.
Innovation Solution
A service redundancy method where an MME acquires MMECs from a DNS server, determines a backup MME, and backs up user information to the DNS server, allowing another MME in the pool to seamlessly take over services when the original MME fails, ensuring continuous service delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standby MME node is deployed to backup a pool of MME nodes and handles journaling or synchronization messages from all MME nodes, then reliability is improved through redundancy, but device complexity increases due to the additional standby node and its configuration requirements
Solution Approach 1:
The active MME nodes perform self-backup by automatically sending user information to peer MME nodes when detecting a failure. Each MME node serves as both a service provider and a backup provider, eliminating the need for a dedicated standby node. This self-service mechanism achieves redundancy while reducing overall system complexity.
Solution Approach 2:
Each MME node in the pool is designed to perform multiple functions: normal service provision, failure detection, and backup service provision. Any MME node can assume the role of a serving MME for UEs originally attached to a failed MME, making the system more flexible and reducing the need for specialized standby components.
2Reliability
If service requests from UEs attached to a faulty MME are rejected by the network side, then reliability is maintained by preventing service failures, but productivity decreases due to service interruptions and re-attach procedures
Solution Approach 1:
MME nodes pre-establish backup relationships with peer MME nodes before failures occur. When an MME failure is detected, the backup MME node already has the necessary user information ready, allowing immediate service continuation without requiring UEs to re-initiate attach procedures or experience service rejections.
Solution Approach 2:
The backup MME node acts as an intermediary that receives service requests for UEs originally attached to a failed MME. Instead of rejecting these requests, the backup MME retrieves user information from the HSS and forwards requests appropriately, preventing service failures while maintaining normal productivity.
3Reliability
If a large quantity of UEs initiate attach procedures simultaneously after an MME failure, then reliability is improved by re-attaching to working MMEs, but HSS congestion occurs due to the signaling impact on network elements
Solution Approach 1:
Backup MME nodes automatically retrieve user information from the HSS in advance and store it locally. When failures occur, UEs can be served using this pre-retrieved information without needing to initiate new attach procedures to the HSS, thereby preventing HSS congestion while maintaining network accessibility.
Solution Approach 2:
User information is pre-fetched from the HSS and stored in backup MME nodes before failures occur. This preliminary action eliminates the need for simultaneous HSS access by multiple UEs during failure recovery, preventing signaling storms and HSS congestion while ensuring continuous network access.
Data Source
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AI summary
Embodiments of the present invention provide a service redundancy method and a related apparatus, which resolve a problem in the prior art that a service redundancy effect is relatively poor. The method includes: sending, by an MME, a request message to a DNS server, where the request message includes a pool identity of an MME pool in which the MME is located; receiving, by the MME, a request response message sent by the DNS server, where the request response message includes MMECs of all MMEs in the MME pool; determining, by the MME, a backup MME of the MME according to the MMECs of all the MMEs in the MME pool; sending, by the MME, an interface request message to the DNS server, where the interface request message includes an MMEC of the backup MME and the pool identity of the MME pool; receiving, by the MME, an interface response message sent by the DNS server, where the interface response message includes interface information of the backup MME; and sending, by the MME according to the interface information of the backup MME, user information of a UE attached to the MME to the backup MME. The method is applicable to the field of communications technologies.