Network Data Transmission Credit Control for Packet Ordering
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Solution Overview
Problem
Data center networks face issues with out-of-order data packet transmission due to limited resources for reordering, leading to inefficiencies and performance degradation, particularly in high-performance computing and cloud-based applications.
Innovation Solution
Implementing a data transmission method that involves a first network device requesting and receiving grant information to determine credit limits for data transmission, switching between packet-distributed and per-flow load sharing based on sequence numbers and cache availability to ensure data packets are reordered correctly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large cache is disposed at the receive-end network device to perform reordering, then out-of-order data packets can be resolved, but chip resources are excessively consumed and caching resources are insufficient
Solution Approach 1:
The patent applies preliminary action by having the receive-end network device send credit information indicating available cache space to the send-end device before data transmission. This allows the send-end device to adjust its transmission rate in advance, preventing the receive-end cache from being overwhelmed and eliminating the need for excessively large cache resources while ensuring reliable data packet ordering.
2Productivity
If packet-distributed load sharing is used to improve transmission efficiency, then data transmission speed increases, but data packets become out of order at the receive-end
Solution Approach 1:
The patent implements feedback by establishing a credit-based control mechanism where the receive-end device continuously monitors its cache status and sends credit information back to the send-end device. This feedback loop allows the send-end device to dynamically adjust its packet transmission rate, maintaining both high transmission efficiency through packet-distributed load sharing and reliable data packet sequencing by preventing cache overflow.
3Reliability
If the ordering cache is filled up due to insufficient caching resources, then data transmission must stop to wait for cache space, but this reduces network performance
Solution Approach 1:
The patent applies dynamics by implementing a dynamic credit-based flow control mechanism where the transmit credit limit is continuously adjusted based on real-time cache availability at the receive-end device. This dynamic adjustment allows the network to maintain high performance by optimizing the transmit rate according to available resources, while ensuring complete reordering reliability by preventing cache overflow that would require transmission stops.
Data Source
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AI summary
This application provides a data transmission method and a network device. The method includes: sending, by a first network device, request information to a second network device; receiving, by the first network device, grant information sent by the second network device, where the grant information includes a first sequence number; determining, by the first network device, a first credit limit based on the first sequence number, where the first credit limit is an amount of data that is allowed to be sent by the first network device in a packet-distributed load sharing manner; and sending, by the first network device, data to the second network device based on the first credit limit. In the foregoing technical solution, the first network device determines, based on the grant information sent by the second network device, the amount of data that is allowed to be sent in the packet-distributed load sharing manner, and further sends data to the second network device based on the amount of data. This can avoid that an amount of data sent exceeds an amount of data that can be cached and ordered by the second network device, thereby avoiding out-of-order sending of data packets from the second network device.