Improving the Packet Send-Time Accuracy in Embedded Devices

A number of projects deploy Linux-based embedded systems to carry out large-scale active network measurement and network experiments. Due to resource constrains and the increase of network speed, obtaining sound measurement results from these low-end devices is very challenging. In this paper, we present a novel network primitive, OMware, to improve the packet send-time accuracy by enabling the measurement application to pre-dispatch the packet content and its schedule into the kernel. By this pre-dispatch approach, OMware can also reduce the overheads in timestamp retrievals and sleeping, and the interference from other application processes. Our evaluation shows that OMware can achieve a microsecond-level accuracy (rather than millisecond-level in a user-space tool) in the interdeparture time of packet trains, even under heavy cross traffic. OMware also offers optimized call for sending back-to-back packet pairs, which can reduce the minimum inter-packet gap by 2 to 10 times. Furthe...

• Type: Journal
• Year: 2015
• Where: PAM
• Authors: Ricky K. P. Mok, Weichao Li, Rocky K. C. Chang
• Keywords: Computer Networks, PAM 2015