WAN Packet Scheduling Queues for Deterministic RDMA Transmission
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Solution Overview
Problem
RDMA services experience significant performance declines due to packet loss and time delay in wide area networks (WANs), particularly when interacting with edge computing centers, leading to increased jitter and unreliability.
Innovation Solution
Implementing a data processing method in network devices located on specified paths between data centers and edge computing centers, where packets of target service types are stored in deterministic scheduling queues and forwarded at predetermined intervals, ensuring bounded and deterministic transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If packets are transmitted through WAN without deterministic scheduling, then network bandwidth utilization is improved, but packet loss and time delay increase due to jitter and uncertainty
Solution Approach 1:
The network device divides packets into different scheduling queues based on service types. High-reliability service packets (e.g., RDMA) are separated into dedicated deterministic scheduling queues, while other packets use default queues. This segmentation allows differentiated handling that maintains high bandwidth utilization while ensuring reliable transmission for critical services.
Solution Approach 2:
The patent changes the scheduling parameter from best-effort (non-deterministic) to deterministic periodic scheduling for high-reliability services. By setting a predetermined scheduling period, the system transforms the transmission characteristics to guarantee bounded time delay and reduce packet loss, while maintaining efficient bandwidth utilization through flexible queue management.
2Loss of time
If deterministic scheduling with predetermined periods is implemented, then time delay and jitter are reduced, but device complexity increases due to additional scheduling mechanisms
Solution Approach 1:
The patent applies deterministic scheduling only to specific high-reliability service packets (local quality) rather than all packets globally. By identifying and treating only RDMA and similar services with predetermined scheduling periods, the system achieves time delay reduction for critical services while keeping the overall device complexity manageable through selective application of the mechanism.
Solution Approach 2:
The implementation uses partial deterministic scheduling - applying predetermined periods only when high-reliability packets are detected, rather than continuously maintaining complex scheduling structures for all traffic. This reduces the average device complexity while still achieving the time delay and jitter reduction benefits when needed.
3Reliability
If packets are buffered in scheduling queues with predetermined periods, then transmission reliability is improved, but transmission speed decreases due to waiting time
Solution Approach 1:
The system uses periodic scheduling with predetermined periods to buffer and forward packets. High-reliability packets are held in dedicated queues and transmitted at regular intervals, ensuring they are not lost due to network jitter while maintaining predictable transmission timing. This periodic action balances reliability improvement with speed preservation.
Solution Approach 2:
The network device performs preliminary classification and queueing of high-reliability packets before transmission. By identifying and placing these packets in deterministic scheduling queues in advance, the system prepares them for reliable transmission without last-minute delays, thus improving reliability while minimizing the impact on transmission speed.
Data Source
AI summary
A data processing method, apparatus, network device and storage medium are disclosed. The method is applied to a network device in a WAN, wherein the network device is located on a specified path from a gateway of a first data center to a gateway of a second data center. The method comprises: storing the acquired first packet of a target service type in a first scheduling queue corresponding to a deterministic flow to which the packet belongs, the source address of the packet is the address of the first host in the first data center, the destination address of the first packet is the address of the second host in the second data center, and the forwarding path of the deterministic flow to which the first packet belongs is the specified path; forwarding the packet in the first scheduling queue when the scheduling period of the first scheduling queue is reached.