SMF DNS Cache Update for 5G Local Traffic Routing
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Solution Overview
Problem
In a 5G network with UPF-based local traffic routing, the DNS cache in User Equipment (UE) is not updated, preventing access to locally deployed applications.
Innovation Solution
The Session Management Function (SMF) obtains and configures the first address information of a local DNS server to the uplink classifier and UE through the Access and Mobility Management Function (AMF), enabling the UE to refresh its DNS cache and route data to the local DNS server for local traffic processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a UPF is inserted as an uplink classifier for local traffic routing, then local traffic routing capability is improved, but the DNS cache in the UE cannot be updated causing inability to access local applications
Solution Approach 1:
The patent segments the DNS resolution process by introducing a local DNS server at the edge network that handles DNS queries independently from the core network DNS. This segmentation allows the UE to resolve domain names locally without requiring core network involvement, thus maintaining access to local applications while enabling local traffic routing.
Solution Approach 2:
The patent introduces an intermediary mechanism where the SMF acts as a mediator to update the UE's DNS configuration. The SMF receives DNS server address information from the PCF and forwards it to the UE, enabling the UE to refresh its DNS cache and access local applications without manual intervention.
2Productivity
If traffic is routed locally through MEC nodes, then burden on core network is reduced, but DNS cache update mechanism is missing preventing application access
Solution Approach 1:
The patent implements a self-service mechanism where the UE autonomously updates its DNS cache by receiving DNS server address information through the AMF and NAS message. This eliminates the need for complex manual DNS cache update procedures while enabling the UE to self-configure for local application access.
Solution Approach 2:
The patent applies preliminary action by pre-configuring the DNS server address information in the network before the UE needs to access local applications. The SMF obtains and stores the local DNS server address in advance, and the AMF makes it available to the UE when needed, ensuring the DNS cache can be updated before application access is required.
3Speed
If the UE uses cached DNS information, then access speed is maintained, but the cached information becomes outdated preventing access to locally deployed applications
Solution Approach 1:
The patent implements a feedback mechanism where the UE's DNS cache status is continuously monitored and updated based on network conditions. When the UE moves to a new network location or when local services are deployed, the system triggers a DNS cache refresh by providing updated DNS server address information through the AMF, ensuring the cache remains valid without requiring continuous manual updates.
Data Source
AI summary
Disclosed are an information processing method and a related network device. The method comprises: a session management function (SMF) obtaining first address information of a local domain name system (DNS) server; sending the first address information to an uplink classifier; and sending, by means of an access and mobility management function (AMF), the first address information to a user equipment (UE), wherein the first address information is used for the UE to update the IP address of local DNS server.