Credit-Based Flow Control for Lossless Ethernet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lossless Ethernet networks do not implement credit-based flow control, leading to packet discard and increased latency when packets are undeliverable, and are not compatible with existing Ethernet frame formats and protocols.
Innovation Solution
Implementing a credit-based flow control system that classifies traffic flows into multiple classes based on criteria and transmits packets only when sufficient flow credits are available at the target port, allowing for efficient bandwidth allocation and management across the network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional lossless Ethernet networks discard packets when undeliverable, then network simplicity is maintained, but latency increases and packet loss occurs
Solution Approach 1:
The patent implements credit-based flow control where credits are allocated in advance to target ports before packet transmission. The initiator port checks credit availability before sending packets, and credits are pre-allocated based on buffer capacity. This preliminary credit allocation prevents packet discards and retransmissions, eliminating the need for reactive error handling and reducing network latency.
2Reliability
If credit-based flow control is implemented in Ethernet networks, then packet transmission reliability improves, but compatibility with existing Ethernet protocols is lost
Solution Approach 1:
The patent makes the credit-based flow control mechanism universal by implementing it within existing Ethernet switch architecture that can handle multiple protocols. The flow control logic operates at the switch fabric level, compatible with standard Ethernet frame formats while enabling advanced credit-based control. This allows the system to maintain Ethernet protocol compatibility while providing enhanced reliability through credit management.
3Reliability
If packets are retransmitted after discarding, then data integrity is maintained, but network throughput decreases
Solution Approach 1:
The patent implements a feedback mechanism where the target port sends credit updates back to the initiator port based on buffer availability. When buffer space becomes available, credits are returned to the initiator, which then continues transmission without discarding packets. This continuous feedback loop ensures data integrity while maintaining high throughput by preventing unnecessary packet drops and retransmissions through proactive credit management.
Data Source
AI summary
In one embodiment, a system includes an initiator port adapted to receive a traffic flow having a plurality of packets and a hardware processor and logic integrated with and/or executable by the processor, the logic being adapted to classify the traffic flow into a traffic class based on at least one criteria related to the traffic flow, the traffic class being selected from a plurality of traffic classes and transmit one or more packets of the traffic flow to a target port designated by the one or more packets of the traffic flow until an amount of flow credits allocated to the target port is insufficient to service additional packets. Other systems, methods, and computer program products for providing credit-based flow control are described in more embodiments.