Flexible Recirculation Bandwidth Management for Network Nodes

Solution Overview

Problem

Conventional network routing equipment experiences latency and packet drops due to variable packet processing times, leading to backups and dropped control packets, which affect quality of service (QoS) and require costly buffering or limited recirculation path bandwidth with lower priority.

Innovation Solution

Implementing a method for flexible bandwidth management using virtual queues and weighted share scheduling to prioritize and queue recirculation path traffic based on average packet length, ensuring sufficient bandwidth allocation and minimizing packet drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If recirculation path traffic is allocated lower priority and limited bandwidth to maintain ingress traffic service quality, then ingress traffic service quality is maintained, but recirculation path processing delays increase and packet drops occur

Engineering Contradiction:

Improveingress traffic service qualityVSAvoidrecirculation path processing delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic bandwidth allocation where the recirculation path bandwidth guarantee is adjusted based on current network conditions and traffic priorities. Instead of static allocation, the system dynamically modifies bandwidth parameters to balance ingress traffic quality with recirculation processing needs, allowing the allocation to adapt to varying load conditions and packet priority levels.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes key parameters including packet length thresholds, bandwidth allocation percentages, and priority levels based on monitored traffic conditions. By adjusting these parameters dynamically, the system optimizes the balance between maintaining ingress service quality and reducing recirculation delays, allowing flexible adaptation to different network states.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If large memory is dedicated for buffering packets on the ingress path to minimize packet drops, then packet reliability improves, but system cost and computational overhead increase

Engineering Contradiction:

Improvepacket delivery reliabilityVSAvoidbuffering system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the buffering function from the traditional large ingress path memory and replaces it with a smaller virtual queue that uses intelligent scheduling and bandwidth management. Instead of relying on extensive physical buffering capacity, the system extracts the essential function of packet retention and achieves it through software-based virtual queuing combined with dynamic bandwidth allocation to the recirculation path.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system creates a virtual copy of the buffering function through software-based virtual queues rather than using extensive physical memory. The virtual queue mechanism replicates the packet holding capability while using minimal actual memory, achieving the same reliability effect through virtualization and intelligent scheduling algorithms.

Inventive Principle:

Principle #26Copying

3Reliability

If recirculation path bandwidth is limited to a small guaranteed amount, then ingress traffic service quality is maintained, but recirculation path packet processing efficiency decreases

Engineering Contradiction:

Improveingress traffic service qualityVSAvoidrecirculation path processing throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic bandwidth allocation where the recirculation path bandwidth guarantee is adjusted based on current network conditions and traffic priorities. Instead of static allocation, the system dynamically modifies bandwidth parameters to balance ingress traffic quality with recirculation processing needs, allowing the allocation to adapt to varying load conditions and packet priority levels.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes key parameters including packet length thresholds, bandwidth allocation percentages, and priority levels based on monitored traffic conditions. By adjusting these parameters dynamically, the system optimizes the balance between maintaining ingress service quality and reducing recirculation delays, allowing flexible adaptation to different network states.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9608926B2Flexible recirculation bandwidth management

Publication Date: 2017.03.28 CISCO TECHNOLOGY INC

AI summary

A method for managing recirculation path traffic in a network node comprises monitoring an input packet stream received at an input port of the network node and monitoring a recirculation packet stream at a recirculation path of the network node. A priority level associated with individual packets of the monitored input packet stream is detected and low priority packets are stored in a virtual queue. The method also includes determining an average packet length associated with packets of the monitored recirculation packet stream. The method further comprises queuing one or more of the low priority packets or the recirculation packets for transmission based on the average packet length and a weighted share schedule.