A perfSONAR User's Group

Per-Packet Provenance Part 0: Introduction

Not at all like the Law Of Thermodynamics, but inevitably calling it to mind, when I considered that I had a lot to write up, and then I decided that the preceding Part 1 would be part of a series, and named it “Per-Packet Provenance” on the spot. The “series” wasn’t very well planned then, […]

Per-Packet Provenance, Part 1: Managing Burst Size To Sidestep Queue Drops

[I'm reporting on work done with the guidance of Darrell Newcomb, and the assistance of John Hess (John guided me too, but that was on other stuff). I should probably also acknowledge the others who have no doubt told me about this in a presentation somewhere, or elsewhere, and I forgot about it.] [update: although […]

Notes On ECS Liva X as a perfSONAR Node

Liva X

Installing Linux and pS tools on ECS Liva X I first heard of the ECS Liva PC in Luke Fowler’s presentation on “PEN – perfSONAR Endpoint Nodes” during a panel session at the 2015 Internet2 Global Summmit. Since then, ECS has brought out a new generation of devices under the Liva brand, and I have […]

Mirabox Arch Linux Install

Various folks around the Club and beyond have been impressed with Globalscale Mirabox, its dual gigabit Ethernets, USB 3.0 ports, CPU and RAM make it a cut above other platforms, hardware-wise, but software support, not so much. The stock kernel lacks kernel functionality to perform such roles as NAT/Firewall/Router, and for some reason, can’t sync […]

Reducing Raspbian Install To Minimum Therbligs With raspbian-ua-netinst

A significant bottleneck in the workflow, when deploying multiple Raspberry Pis is the SD card preparation and then the individual machine config. The default workflow, for the young experimenter market that the Raspberry targets, is to write an SD card, boot the Raspberry Pi from it, connect a keyboard and monitor and answer questions. Fun […]

Temp/Humidity with Raspberry Pi

  Found myself answering this question at the recent Internet2 Tech Exchange in Indianapolis – Can you add temperature and/or humidity sensors to these small devices easily? I have done this with Raspberry Pi more than once. I took old ribbon cables from floppy drives, shortened one connector with a hacksaw, and then cut the […]

Beaglebone Black node logistics Q&A from Lonnie @ LONI

I got a set of good questions from Lonnie Leger, and as I was answering, I thought, this might read well as a post… With his permission, I paste (one or two after-thoughts in parentheses ). =================================================== Probably useful to note that LSU has some Beaglebone Blacks doing things on their network, perhaps for the […]

Little Boxes In The Internet Monitoring Biz

Over the last decade and a half, I often paused to wonder about using small computers for network assessment. The market seemed to be made up of exciting press releases about product that no retailer had in stock, or if they did, there was a prohibitive minimum quantity for purchase. Less than two years ago, […]

Switch buffer size

I gave a lightning talk in 2010 at Joint Techs that reviewed measurements that show empirically how buffer size affects bwctl throughput. I partitioned the buffer RAM on a Catalyst 6500 Gig-E port to different queues. I set the RED parameters to get pure tail drop performance. The bwctl tests were done to the best […]

Iperf “self-tests”

From a performance-node-users@internet2.edu thread: https://lists.internet2.edu/sympa/arc/performance-node-users/2013-05/msg00048.html Answer from Ezra Kissel at I.U. , which illuminates some things perhaps relevant to understanding throughput and tester validation. My original question: What is the value or meaning of results from a “self test”, as would occur when one runs an iperf server on a host, and then runs the client […]

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