Network Bridge VLAN Mapping for 4096 Limit
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Solution Overview
Problem
Current network systems, such as those using IEEE 802.1Q, are limited to supporting only 4096 virtual local area networks (VLANs) due to the 12-bit VLAN identifier, which restricts their capacity to handle increasing customer demands for speed and performance in communications networks.
Innovation Solution
The solution involves a network bridge that identifies VLAN forwarding information based on the interface associated with a packet, rather than directly accessing it based on the VLAN identifier, allowing for the support of more than 4096 independent VLANs by using a 12-bit 802.1Q compliant VLAN identifier and mapping it into an internal number for lookup operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a 12-bit VLAN identifier is used according to IEEE 802.1Q standard, then the network bridge can efficiently identify and forward frames using direct lookup, but the network bridge is limited to supporting only 4096 VLANs
Solution Approach 1:
The patent introduces an intermediary component (VLAN identifier mapping module) that maps the 12-bit VLAN identifier to an extended VLAN identifier. This mapping mechanism acts as a mediator between the standard 802.1Q VLAN identification system and the extended VLAN support requirement, enabling the network bridge to support more than 4096 VLANs while maintaining compatibility with the standard lookup efficiency
Solution Approach 2:
The patent extends the VLAN identification space by adding another dimension to the VLAN identifier structure. Instead of directly using the 12-bit VLAN identifier for lookup, the system creates an extended identification space through mapping, effectively transitioning from a single-dimensional (12-bit) identifier to a multi-dimensional identification system that can accommodate more than 4096 VLANs
2Adaptability or versatility
If the network bridge supports more than 4096 VLANs using extended identification, then the network capacity increases, but the complexity of VLAN identification and forwarding increases
Solution Approach 1:
The patent applies preliminary action by pre-establishing a mapping relationship between the 12-bit VLAN identifier and the extended VLAN identifier before frame forwarding occurs. The mapping table is prepared in advance, allowing the network bridge to perform efficient lookups without complex real-time calculations, thus reducing the operational complexity despite supporting more VLANs
Data Source
AI summary
Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, mechanisms, and means for supporting a large number of virtual local area networks (VLANS) in a bridged network. Packets are received that include 802.1Q Virtual Local Area Network (VLAN) identifiers (VIDs). However, rather than accessing the VLAN forwarding information directly based on the VID as conventionally performed, the VLAN forwarding information to use for a particular packet is determined based on an interface (e.g., virtual or physical interface, port, MPLS label, GRE tunnel or other abstraction of the interface). In other words, the interface associated with the packet identifies a context for determining the VLAN forwarding information based on the VID included in the packet. Therefore, network bridging devices can support more VLANs than that imposed by the 4096 possible values of a VID.