Active Client List for Layer 3 Roaming in Wireless Networks
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Solution Overview
Problem
Current WLAN technologies face challenges in maintaining IP connectivity and seamless roaming across different subnets, leading to potential disruptions in applications like VoIP and streaming due to the lack of standardized mechanisms for layer 3 roaming, resulting in sub-optimal routing and increased latency.
Innovation Solution
The implementation of a registration server and a mesh network of wireless switches that maintain an active client list with registration information, allowing clients to roam between subnets while retaining their original IP address through IP tunneling and Dynamic Host Configuration Protocol (DHCP) management, ensuring continuous IP connectivity and reducing re-authentication needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a client roams between different IP subnets in a WLAN, then the client can access different network areas, but the IP connectivity is disrupted and the client must obtain a new IP address
Solution Approach 1:
The patent introduces a wireless switch as an intermediary device between the client and the DHCP server. The wireless switch intercepts DHCP requests from roaming clients and forwards them to the appropriate DHCP server, enabling the client to obtain and maintain an IP address while roaming across different subnets without direct client-server communication
Solution Approach 2:
The patent implements preliminary registration of wireless switches and pre-establishment of DHCP relay agents before clients roam. The system proactively sets up the necessary routing and DHCP relay configurations in advance, so when a client roams to a new subnet, the IP connectivity is already prepared and maintained without disruption
2Device complexity
If conventional WLAN roaming is implemented without layer 3 support, then the system is simpler to manage, but routing becomes sub-optimal and latency increases
Solution Approach 1:
The patent segments the WLAN into multiple IP subnets, each managed by its own DHCP server and wireless switch. This segmentation allows clients to roam within subnets quickly while inter-subnet roaming is handled through standardized DHCP relay mechanisms, optimizing routing paths and reducing latency without requiring complex end-to-end management
3Quantity of substance
If clients obtain new IP addresses when roaming to different subnets, then the network can support more clients across subnets, but active sessions are disrupted and re-authentication is required
Solution Approach 1:
The patent ensures continuity of DHCP lease assignments across subnet boundaries. When clients roam between subnets, the wireless switches coordinate to maintain the same DHCP lease, allowing clients to keep their IP addresses and active sessions without re-authentication, thus eliminating time loss while supporting multiple clients across subnets
Data Source
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AI summary
Techniques are provided for creating an active client list that can be distributed to wireless switches. The wireless switches are located in a wireless local area network comprising a registration server, active clients, and wireless switches. Registration information associated with the active clients is communicated to the wireless switches that support those active clients. The registration information associated with the active clients is communicated over an IP tunnel to the registration server. An active client list can then be created using the registration information for each active client. The active client list comprises a record for each active client in the wireless local area network. The record of each client comprises a MAC address of the client, a client IP address of the client, a home switch of the client, a visited switch of the client, inactivity timers for the home switch and the visited switch and location information. The active client list and the registration information for each active client can be communicated to each wireless switch.