UPF Session Migration via SMF Intermediary
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Solution Overview
Problem
Current 5G network architectures face challenges in managing session migration efficiently, particularly when a UPF network element fails, as autonomous migration by the UPF leads to complex backup relationships and significant overheads in processing session backup messages.
Innovation Solution
A method where a network device determines the need for session migration on a UPF network element, sends configuration information and IP address segments to a secondary UPF, and initiates a message to restore sessions, allowing for flexible takeover and reducing the complexity of managing backup relationships.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If session migration is autonomously performed by a single UPF network element, then the UPF can independently manage session migration, but when the entire UPF network element is faulty, no UPF network element can take over the session
Solution Approach 1:
The SMF network element is introduced as an intermediary to manage session migration and UPF selection. When a UPF fails, the SMF can select a new UPF to take over the session, ensuring reliability while maintaining autonomous migration capabilities. The SMF acts as the mediator that coordinates between UPFs and manages session state information.
2Reliability
If session migration is performed between multiple UPF network elements, then session takeover is possible during failure, but a complex function of managing backup relationships and large quantity of overheads are required
Solution Approach 1:
The complex backup relationship management function is extracted from the UPF network elements and placed in the SMF network element. The UPFs no longer need to autonomously manage backup relationships or coordinate failover with each other. Instead, they simply execute migration commands from the SMF, significantly reducing their complexity while maintaining reliability through SMF-coordinated multi-UPF migration.
3Reliability
If session migration is performed between multiple UPF network elements, then session takeover is possible during failure, but a large quantity of overheads are caused by processing session backup messages
Solution Approach 1:
The SMF network element serves as an intermediary that consolidates session state information and coordinates migration between UPFs. This eliminates the need for multiple UPFs to exchange extensive backup messages with each other. The SMF maintains the session state and sends targeted migration commands to the appropriate UPF, significantly reducing message processing overheads while ensuring reliable session takeover.
Data Source
AI summary
Embodiments provide a method, a device, and system to implement session management on a UPF network element. The method includes: determining, by a network device, that a first logical interface group on a first UPF network element needs to be migrated; determining, by the network device, a second UPF network element for the first logical interface group; sending, by the network device to the second UPF network element, configuration information of the first logical interface group and information about a first IP address segment corresponding to the first logical interface group, to restore the configuration information of the first logical interface group and the information about the first IP address segment on the second UPF network element; and sending, by the network device, a first message used to restore, on the second UPF network element, information about one or more sessions corresponding to the first logical interface group.