Datapath Forwarding Device Segmentation for Packet Processing

Solution Overview

Problem

Data center switches are inefficient in handling packets that require advanced services, leading to bottlenecks and increased latency, as they are designed primarily for processing packets matching lookup rules and lack the memory and programmability to maintain connection states for advanced networking services.

Innovation Solution

A datapath forwarding device combining dedicated hardware and a configurable software unit to process packets, allowing for efficient handling of both rule-matching and non-rule-matching packets, with the software unit capable of generating or modifying rules and applying advanced services, such as DDoS protection and firewall services, within the data path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dedicated hardware units are used for packet processing, then processing speed and efficiency are improved, but the ability to handle packets requiring advanced services deteriorates due to lack of memory and programmability

Engineering Contradiction:

Improvepacket processing efficiencyVSAvoidcapability to handle advanced services

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The system segments packet processing into two distinct paths: a fast path handled by dedicated hardware units for routine packets matching lookup rules, and a slow path handled by general-purpose processors for packets requiring advanced services. This segmentation allows each component to specialize in its optimal function, resolving the contradiction between processing efficiency and service capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A control plane processor acts as an intermediary between the hardware forwarding unit and the slow path processing. It generates and modifies rules tables, manages connection states, and coordinates between the hardware and software components, enabling the hardware to handle advanced services by providing it with the necessary programmability and state information.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If general-purpose processors are used for advanced services, then service capability is improved, but CPU and memory requirements and latency increase

Engineering Contradiction:

Improveservice handling capabilityVSAvoidprocessing latency

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system segments packet processing into two distinct paths: a fast path handled by dedicated hardware units for routine packets matching lookup rules, and a slow path handled by general-purpose processors for packets requiring advanced services. This segmentation allows each component to specialize in its optimal function, resolving the contradiction between processing efficiency and service capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The control plane processor performs preliminary actions by pre-generating and storing rules tables in the hardware unit before packets arrive. This allows the hardware to quickly match packets against pre-computed rules without requiring real-time computation, reducing latency for packets that can be handled by the hardware.

Inventive Principle:

Principle #10Preliminary action

3Speed

If hardware units process all packets, then processing speed is improved, but the ability to maintain connection states for advanced services deteriorates

Engineering Contradiction:

Improvepacket forwarding speedVSAvoidconnection state maintenance

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

A control plane processor acts as an intermediary between the hardware forwarding unit and the slow path processing. It generates and modifies rules tables, manages connection states, and coordinates between the hardware and software components, enabling the hardware to handle advanced services by providing it with the necessary programmability and state information.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback mechanisms where the slow path processing provides connection state information and service requirements back to the control plane, which then updates the hardware rules tables accordingly. This feedback loop ensures that the hardware has up-to-date information for maintaining connection states while preserving fast processing speeds.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10623309B1Rule processing of packets

Publication Date: 2020.04.14 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A packet forwarding device and a system using same are provided. The packet forwarding device includes a datapath forwarding hardware unit for processing a first set of packets matching a first set of rules of a rules table. The packet forwarding device further includes a datapath forwarding software unit for generating or modifying the rules table and for processing a second set of packets matching a second set of rules of the rules table and applying a service to the second set of packets.