Service Communications Proxy Unhealthy Endpoint Filtering for 5G NF Discovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 5G networks, Network Function (NF) instances may be reported as available by the NF Repository Function (NRF) despite being unreachable from consumer NFs due to network congestion or impairment, leading to increased latency from reselection processes by the Service Communications Proxy (SCP).
Innovation Solution
The SCP maintains an unhealthy endpoint database to identify and mark unreachable NF instances, and modifies discovery requests to exclude these instances, with the NRF filtering out unreachable NF profiles in its response, allowing optimized routing to reachable NF instances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the NRF returns all registered producer NF instances to consumer NFs, then the completeness of service profile information is improved, but the latency increases due to reselection processes when some instances are unreachable
Solution Approach 1:
The SCP performs preliminary actions by maintaining an unhealthy endpoint database that pre-identifies unreachable producer NF instances. Before the consumer NF receives the service profile list from the NRF, the SCP has already marked problematic endpoints as unhealthy, enabling the NRF to filter them out and return only reachable instances, thus avoiding latency caused by reselection processes.
Solution Approach 2:
The SCP acts as an intermediary between the consumer NF and the NRF. It modifies the discovery request by adding unhealthy endpoint information, and the NRF uses this information to filter service profiles. This intermediary mechanism allows the system to maintain complete service profile information while excluding unreachable instances, resolving the contradiction between information completeness and latency reduction.
2Reliability
If the SCP performs reselection process when a producer NF instance is unreachable, then the service delivery reliability is improved, but the network efficiency deteriorates due to increased latency
Solution Approach 1:
The system performs preliminary identification of unhealthy endpoints and filters them out before service request routing. By maintaining an unhealthy endpoint database and using it to modify discovery requests, the NRF can return only reachable producer NF instances, eliminating the need for reselection processes and thus maintaining service delivery reliability while improving network efficiency.
Solution Approach 2:
The unhealthy endpoint database serves as a feedback mechanism that continuously tracks the reachability status of producer NF instances. This feedback information is used to modify discovery requests, ensuring that the consumer NF receives an updated list of reachable instances, thereby maintaining service delivery reliability without requiring reselection processes that would reduce network efficiency.
3Loss of information
If the NRF includes all service profiles in its response, then the information completeness is improved, but the reselection process frequency increases when unreachable instances are selected
Solution Approach 1:
The SCP acts as an intermediary that modifies the discovery request by incorporating unhealthy endpoint information from the unhealthy endpoint database. The NRF then uses this information to filter service profiles, returning a complete list of reachable producer NF instances. This intermediary mechanism ensures information completeness while eliminating reselection processes by pre-filtering unreachable instances.
Solution Approach 2:
The system performs preliminary filtering of service profiles by the NRF based on unhealthy endpoint information provided by the SCP. This preliminary action ensures that the consumer NF receives a complete list of reachable instances from the outset, preventing the need for reselection processes and maintaining both information completeness and low reselection frequency.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for optimized NF discovery and routing includes, at an SCR, receiving a discovery request message or generating a discovery request message in response to a received service request message with a 3gpp-Sbi- Discovery header. The SCR modifies the discovery request message to identify as unhealthy at least one service endpoint and service name combination associated with at least one producer NF instance capable of providing a service identified in the discovery request message or the service request message The SCR forwards the discovery request message to the NRF. The NRF creates a list of service profiles of producer NF instances capable of providing the service identified in the discovery or service request message and excludes, from the list, at least one service profile of the at least one producer NF instance corresponding to the endpoint and service name combinations identified as unhealthy in the discovery request message.