Service Function Chain Transition in 5G Networks
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Solution Overview
Problem
Current methods for modifying service function chains in communications networks, such as 5G networks, often result in disruptions to user sessions, particularly when packets are being handled by service functions that modify traffic, leading to dropped connections and sub-optimal service experiences due to the need to destroy and recreate service chains.
Innovation Solution
A method that involves determining a new service function chain with updated policy control rules, allowing for a smooth transition of sessions from an existing service function chain to a new one without dropping TCP connections, by pre-configuring the new chain based on the packet modifications performed by the original service function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If service function chains are modified by destroying and recreating them, then service function updates can be implemented, but TCP connections are dropped and service continuity is disrupted
Solution Approach 1:
The patent applies preliminary action by pre-configuring a new service function chain before destroying the old one. The new SFC is set up with all necessary service functions and packet detection rules in advance, ensuring that when the transition occurs, there is no interruption in service. This allows the system to update service functions while maintaining continuous TCP connections.
Solution Approach 2:
The patent uses an intermediary approach by introducing a transitional mechanism where the new service function chain acts as a bridge. The system maintains both the old and new SFC configurations temporarily, allowing seamless traffic redirection. This intermediary state ensures that no packet loss occurs during the transition from old to new service functions.
2Adaptability or versatility
If service function chains are updated to include new service functions, then service capabilities are enhanced, but service disruption occurs during the transition
Solution Approach 1:
The system performs preliminary configuration of the new service function chain including all service functions and packet detection rules before the actual transition. This ensures that when the update occurs, the new configuration is ready and waiting, eliminating service disruption and making the transition smooth and operationally easy.
Solution Approach 2:
The patent ensures continuity of useful action by maintaining service function operations throughout the transition process. The new service function chain is configured and activated without interrupting the service flow, allowing the system to enhance capabilities while maintaining continuous operational smoothness.
3Device complexity
If packet detection rules are not pre-configured for the new service function chain, then configuration complexity is reduced, but service disruption occurs during chain transition
Solution Approach 1:
The system applies preliminary action by configuring packet detection rules in advance as part of the new service function chain setup. All necessary PDRs are created and associated with the new SFC before the transition occurs, ensuring that packet routing is immediately functional when the switch happens, maintaining service continuity without adding operational complexity.
Data Source
AI summary
A method (700) in a policy control function, PCF, of moving a session from a service function chain, SFC, to a new SFC, wherein the SFC comprises a first SF that modifies packets in the session. The method comprises determining (702) to update a second SF in the SFC for the session, determining (704) a new SFC for the session comprising new SFs, wherein the new SFs are selected based on the determined update to the second SF and information related to the packet modification performed by the first SF and (706) sending a first message to a session management function, SMF, comprising updated policy control rules for the session, wherein the updated policy control rules comprise an indication of the new SFC for the session.