Intel E830网卡上定时传输与硬件时间戳的实验评估

中文摘要 AI 辅助

高精度报文传输在确定性网络应用中愈发重要，包括5G前传和时间敏感网络（TSN）。部分近期高速网卡（NIC），如Intel E830和NVIDIA ConnectX系列，支持指定时间的硬件辅助传输，以及接收和发送帧的硬件时间戳。尽管这些功能与5G前传的严格时序要求密切相关，但关于其时序精度和性能特征的公开信息很少。作为我们之前对NVIDIA ConnectX系列定时传输研究的配套工作，本文对Intel E830网卡的定时传输和硬件时间戳功能进行实验表征。使用基于FPGA的测量平台（具备确定性报文生成和纳秒级时间戳功能），我们评估了接收和发送硬件时间戳以及定时传输精度。结果显示，硬件时间戳的时序变化仅为几纳秒：接收时间戳得出的报文间隔峰峰值变化最高达6 ns，发送时间戳比较在时钟漂移补偿后剩余范围为4.6 ns。约99%的观测报文间隔在目标间隔的±300 ns范围内，偶尔出现高达约2 us的异常值。这些结果表明，定时传输可支持时序要求为几十微秒级的应用，如5G前传，但可能无法满足要求几纳秒到几十纳秒级传输时序精度的TSN应用。

英文摘要

High-precision packet transmission is increasingly important in deterministic networking applications, including 5G fronthaul and Time-Sensitive Networking (TSN). Some recent high-speed network interface cards (NICs), including the Intel E830 and NVIDIA ConnectX series, support hardware-assisted transmission at specified times and hardware timestamping of received and transmitted frames. Despite the relevance of these capabilities to the stringent timing requirements of 5G fronthaul, little public information is available on their timing accuracy and performance characteristics. As a companion to our previous study of scheduled transmission on the NVIDIA ConnectX series, this paper experimentally characterizes the scheduled transmission and hardware timestamping capabilities of the Intel E830 NIC. Using an FPGA-based measurement platform with deterministic frame generation and nanosecond-resolution timestamping, we evaluate receive and transmit hardware timestamping and scheduled-transmission accuracy. The results show only several-nanosecond timing variation in hardware timestamping. Receive timestamp-derived frame intervals showed a peak-to-peak variation of up to 6 ns, while the transmit timestamp comparison showed a residual range of 4.6 ns after clock-drift compensation. Approximately 99% of the observed frame intervals were within $\pm$300 ns of the target interval, with occasional outliers of up to approximately 2 us. These results indicate that scheduled transmission can support applications with timing requirements on the order of several tens of microseconds, such as 5G fronthaul, but may be insufficient for TSN applications requiring transmission timing accuracy on the order of a few to a few tens of nanoseconds.

发表机构

• Intelligent Platform Research Institute (IPRI), National Institute of Advanced Industrial Sciences and Technology (AIST)（先进产业科学技术研究所智能平台研究所）

机构由 AI 辅助整理，请以论文原文为准。