RDMA Payload Direct Memory Storing for Out-of-Order Packet Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current RDMA technologies are limited by the assumption that all packets for a specific transport flow must travel across the same network path, restricting in-order packet delivery and limiting network utilization.
Innovation Solution
The implementation of Payload Direct Memory Storing (PDMS) mechanisms allows for out-of-order packet delivery in the transport layer by accepting packets on arrival, scattering them to memory or data buffers, and reordering them on the target device, without defining how reordering is implemented, supporting multiple network paths and reducing re-transmission overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If packets are delivered in-order through a single network path, then transport operation reliability is ensured, but network utilization is limited and bandwidth degradation occurs
Solution Approach 1:
The patent segments the transport flow into multiple independent packet streams that can traverse different network paths simultaneously. Each packet is assigned to a specific path based on routing rules, allowing parallel transmission while maintaining the ability to reconstruct the original data sequence at the destination through reordering buffers.
Solution Approach 2:
The patent introduces reordering buffers as intermediary components at the destination device. These buffers temporarily store out-of-order arriving packets and reorder them into the correct sequence before delivering to the application layer, thus mediating between the parallel network paths and the sequential transport protocol requirements.
2Productivity
If multiple network paths are used for packet transmission, then network utilization is enhanced, but packet reordering complexity increases
Solution Approach 1:
The patent applies preliminary action by embedding path identification information and sequence markers in packet headers before transmission. This pre-tagging approach allows the destination device to efficiently identify and reorder packets without complex real-time analysis, reducing the reordering complexity while supporting multiple network paths.
3Reliability
If in-order packet delivery is enforced, then transport protocol compliance is maintained, but re-transmission overhead increases
Solution Approach 1:
The patent introduces dynamic packet routing where packets can be directed along different paths based on network conditions and path availability. The system dynamically adjusts routing decisions while maintaining protocol compliance through reordering, reducing the need for re-transmissions that would otherwise be required to enforce strict in-order delivery.
Data Source
AI summary
Technologies for payload direct memory storing (PDMS) for out-of-order delivery of packets in remote direct memory access (RDMA) are described. A responder device includes an RDMA transport layer that can receive packets out of order and allow direct data placement of packet data in order. The responder device receives a first packet with a first packet number and first location information. The responder device stores first packet data to a first location according to the first location information. The responder device also receives a second packet and stores second packet data to a second location according to the second location information. A second packet number indicates that the first packet is received out of order. The first and second packet data are stored in order. The responder device can provide an indication that a message has arrived in response to determining that all packets of the message have arrived.