Network Processor Lookup Table Dynamic Forwarding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional network processor designs face complexity and limited extensibility due to the need for multiple static forwarding pipelines to support different routing protocols, making it difficult to accommodate routing protocol changes or new standards without redesigning the hardware.
Innovation Solution
A network processor architecture that uses a hardware lookup table to determine operational flows for forwarding decisions, allowing a single pipeline to be dynamically configured through mode values stored in a results table, which can be programmed to support various routing protocols, including custom modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple static forwarding pipelines are implemented in hardware to support different routing protocols, then the network processor can handle various routing functions, but the hardware design complexity increases significantly
Solution Approach 1:
The patent implements a dynamic forwarding pipeline where the operational flow is determined at runtime through hardware lookup tables rather than being statically fixed at design time. The network processor can dynamically switch between different forwarding behaviors (unicast, multicast, PIM-SM, PIM-DM, PIM-BIDIR, PIM-SSM) by updating lookup table entries, allowing a single hardware pipeline to adapt to different routing protocols without requiring multiple dedicated pipelines.
Solution Approach 2:
The patent changes the operational parameters of the forwarding pipeline by storing mode values in hardware lookup tables that identify different operational flows. By modifying the lookup table contents (parameters), the system can support different routing protocols without changing the underlying hardware structure, thus reducing design complexity while maintaining versatility.
2Adaptability or versatility
If multiple static forwarding pipelines are implemented in hardware to support different routing protocols, then the network processor can handle various routing functions, but the overall operating speed is constrained
Solution Approach 1:
The patent employs a dynamic lookup table-based forwarding mechanism that allows the network processor to operate at wire speed by determining the appropriate forwarding pipeline through fast hardware table lookups rather than through complex static pipeline selection logic. This dynamic approach enables single-pipeline operation at maximum speed while still supporting multiple routing protocols through runtime configuration.
3Device complexity
If forwarding pipelines are made static at design time, then the hardware implementation is simplified, but the system cannot be extended to support routing protocol changes or new standards
Solution Approach 1:
The patent creates a dynamically configurable forwarding pipeline where a single hardware implementation can support current and future routing protocols through runtime updates to hardware lookup tables. The mode values stored in these tables identify operational flows that can be updated to accommodate new routing protocol standards without requiring hardware redesign, thus achieving both simplicity and extensibility.
Solution Approach 2:
The patent designs a universal forwarding pipeline that can perform multiple routing functions through a single hardware structure. By using hardware lookup tables to store mode values that identify different operational flows (unicast, multicast, various PIM modes), the system achieves multi-functionality without duplicating hardware pipelines, enabling easy extension to new protocols through software-driven configuration.
4Adaptability or versatility
If multiple static forwarding pipelines are implemented in hardware, then different routing functions can be supported, but the hardware design requires pre-classification logic which complicates the design
Solution Approach 1:
The patent extracts the classification logic from the forwarding pipeline itself and relocates it to hardware lookup tables. Instead of having complex pre-classification logic embedded in multiple static pipelines, the system uses a single pipeline with lookup tables that store mode values identifying the appropriate operational flow. This separation simplifies the forwarding pipeline while maintaining the ability to differentiate between various routing functions.
Data Source
AI summary
Techniques for customizing forwarding decisions in a network device via a hardware lookup table result are provided. In one embodiment, a network processor of the network device can perform a lookup into a lookup table based on one or more sections of a received packet. The network processor can then determine, based on the lookup, an entry in the lookup table and retrieve, using a pointer included in the lookup table entry, a mode value from a results table. The mode value can identify an operational flow (e.g., a series of forwarding decisions) to be carried out by the network processor for forwarding the received packet.