UPF ARP Cache Interception to Avoid Paging Storms

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Solution Overview

Problem

In 5G networks, the current technologies face challenges in avoiding paging storms during ARP broadcast and NDP multicast, leading to unnecessary occupation and wastage of network resources, especially when many UEs are in CM-IDLE state, as they rely on deep packet inspection which is compute-intensive and inefficient.

Innovation Solution

Building an ARP cache/IPv6 Neighbour Cache at the UPF entity without performing deep packet inspection for every packet traversed, allowing the cache to intercept and respond to ARP requests locally, thereby avoiding broadcast/multicast and reducing resource hogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If deep packet inspection is performed for every packet traversed to build ARP cache, then the ARP cache can be populated accurately, but compute resources are excessively consumed and network efficiency deteriorates

Engineering Contradiction:
ImproveARP cache accuracyVSAvoidcompute resource usage
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the ARP cache population function from deep packet inspection by utilizing existing DHCP snooping tables and ARP inspection mechanisms. Instead of inspecting every packet deeply, the system extracts ARP cache information from dedicated protocol exchanges, significantly reducing compute overhead while maintaining cache accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary action by populating the ARP cache through DHCP snooping and ARP inspection before actual ARP broadcast needs occur. This proactive population using dedicated protocol exchanges prepares the cache in advance, eliminating the need for resource-intensive deep packet inspection during critical ARP operations.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If ARP broadcast is sent to all UEs in the network, then address resolution can be achieved, but paging storms occur and network resources are wasted

Engineering Contradiction:
Improveaddress resolution capabilityVSAvoidnetwork resource wastage
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The system performs preliminary action by pre-populating the ARP cache through DHCP snooping and ARP inspection mechanisms before ARP broadcast is needed. This advance preparation ensures that when address resolution is required, the responding UE's MAC address is already available in the cache, eliminating the need for broad ARP broadcasts and preventing paging storms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The UPF acts as an intermediary by maintaining the ARP cache and intercepting ARP requests. Instead of allowing ARP broadcasts to propagate through the entire network, the UPF intermediates by checking its cache and directly responding to ARP requests, thereby preventing unnecessary network-wide paging storms while maintaining address resolution capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4054278B1Methods and apparatuses for avoiding paging storm during ARP broadcast for ethernet type pdu
Publication Date: 2024.06.26 HUAWEI TECH CO LTD
  • EP4054278B1 patent drawingFigure 1~2
  • EP4054278B1 patent drawingFigure 3
  • EP4054278B1 patent drawingFigure 4~5

AI summary

Methods and apparatuses for acquisition of address resolution protocol (ARP)/ IPv6 Neighbour cache at user plane function (UPF) entity without performing deep packet inspection for every packet that traverses are disclosed. The principal behind the present invention is for the ARP broadcast / ICMPv6 Neighbour Solicitation multicast from any Ethernet client (UE or clients behind UE or clients in DN) to be responded by UPF entity itself, by looking up the ARP/ IPv6 Neighbour cache built in the UPF entity, irrespective of whether the UPF entity acts as the core Ethernet switch or the core Ethernet switch is in the DN. The solution is simplified to always intercept ARP at the UPF and respond to it based on local ARP / IPv6 Neighbour cache.