Learning from Facebook’s Mistakes

It was only a few weeks back, in July of this year, where I remarked that an Akamai report of an outage was unusual for this industry. It was unusual in that it was informative in detailing their understanding of the root cause of the problem, describing the response that…


IAB Workshop on Measuring Network Quality for End Users

The telephone network had a remarkably clear overriding service objective: It had to sustain a human conversation. Now this must be able to carry a signal which is a human voice. To be discernible to human listeners, its necessary to carry audio frequencies of between 300 and 3,500 Hz. Most…


Outage Reporting

Much has been said about the criticality of the small coterie of large-scale content distribution platforms and their critical role in today’s Internet. These days when one of the small set of core content platforms experiences a service outage then it’s mainstream news, as we saw in June of this…


Notes from NANOG 81

As the pandemic continues, the network operational community continues to meet online. NANOG held its 81st meeting on February 8 and 9, and these are my notes from some of the presentations at that meeting. A Brief History of Router Architecture Ethernet, developed in 1973 at Xerox PARC, was a…


Deep Sea Diving

Last month I attended the New Zealand Network Operators’ Group meeting (NZNOG’20). One of the more interesting talks for me was given by Cisco’s Beatty Lane-Davis on the current state of subsea cable technology. There is something quite compelling about engineering a piece of state-of-the-art technology that is intended to…


BGP in 2019 – Part 2

The first part of this report looked at the size of the routing table and looked at some projections of its growth for both IPv4 and IPv6. However, the scalability of BGP as the Internet’s routing protocol is not just dependant on the number of prefixes carried in the routing…


BGP in 2019 – Part 1

It has become a tradition (or quite possibly a habit) each January for me to report on the behaviour of the inter-domain routing system over the past year, looking in some detail at some metrics from the routing system that can show the essential shape and behaviour of the underlying…


Sizing the Buffer

Packet switched networks benefit from buffers within the network’s switches. In the simplest case, if two packets arrive at a switch at the same time and are destined to the same output port, then one packet will need to wait in a buffer while the other packet is sent on,…


What’s the Time?

Computers have always had clocks. Well maybe not clocks as you might think, but digital computers have always had oscillators, and if you hook the oscillator to a simple counter then you have a clock. The clock is not just there to tell the time, although it can do that,…


BGP in 2017

It has become either a tradition, or a habit, each January for me to report on the experience with the inter-domain routing system over the past year, looking in some detail at some metrics from the routing system that can show the essential shape and behaviour of the underlying interconnection…