Working with YANG Models - A brief intro to 'pyangbind'

              · · ·

Both the Hawaii IETF meeting (IETF91) and the subsequent meeting we had a few weeks ago in Dallas were somewhat YANG-heavy. Following work to move towards YANG as a standard modelling language for network configuration, and the subsequent IESG statement effectively deprecating SNMP as the way that we present network configuration - the IETF, and especially the routing area, has dived head-first into YANG. Indeed, I’ve been occupied somewhat with some really great collaborative work with a number of awesome engineers from Google, Microsoft, AT&T, Level3, Yahoo!

March 2013 - December 2014 on TfL


Oyster usage data from TfL for my Oyster card, March 2013 - December 2014. Data visualisation is with D3.js - mouse-over a station to isolate journeys to and from that location. Larger version.

RFC5218, RSVP-TE and Segment Routing.

              · · · · · ·

After my presentation at UKNOF on SR, Mark Townsley asked me whether I’d be interested in presenting to his class at the Ecole Polytechnique in Paris, around the thinking (from an ops perspective) of delivering the 5218 concept of “net positive value” through the SR technology, and how the existing protocols that are available might measure up against the criteria that 5218 gives us to consider. We managed to co-ordinate logistics, and I presented to INF566 on Wednesday afternoon, which was a really cool experience.

SPRING Forward(ing)

              · · · · · ·

I recently gave a talk at UKNOF relating to Segment Routing/SPRING and the operational challenges that we are trying to resolve through it. You can see it on YouTube below - or the slides are on this site - SPRING Forward(ing) - UKNOF27   

Almost Two Years On: Where is SDN?

              · ·

Almost two years ago I wrote a post on this site entitled Some Initial Thoughts on the SDN. Clearly, since then the SDN concept gained some more legs (and entered a new stage of the hype cycle) - so, where are we right now? Firstly, I think its fair to say that the concept presented by Scott Shenker of having a single centralised computational element controlling COTS OpenFlow-speaking switches has fallen out of favour somewhat (based on the discussions with other network architects, engineers, and implementors that I have had).

Speed of Internet Innovation.

              · ·

A question that came up at an event I was at yesterday: How will the time between the first (commercial) deployment of a telephony service, and a regulated universal service obligation for telephony compare to that of the time between the first (commercial) Internet services being deployed and a USO for IP connectivity (e.g., Broadband)? Based on this, is the cycle time of the telephony regulatory bodies, and mechanisms through which changes are implemented within these bodies suitable for Internet services?

Reinforcing the Kitchen Sink - Another BGP Presentation

              · · · · ·

On Friday, I presented at the Netnod meeting in Stockholm, Sweden - again about BGP error handling - this time presenting a bit of an update as to why this continues to be a problem for the Internet (and private BGP deployments) - and why this work is still really relevant. In addition, I tried to give an overview of what the solution space looks like. I’m not sure whether there’s video, but as usual, the slides are linked below!

Some Initial Thoughts on the Software-Defined Network (SDN).

              · · · · ·

At one of the Ericsson R&D days, Professor Scott Shenker - who's an academic at the University of California in Berkeley, presented on a concept that he calls the "software defined network'. Now, if you haven't seen the presentation - it's definitely worth watching (it's on YouTube, here), and provides quite an engaging look at the problem of network scaling from the perspective of academia, and especially in terms of a comparison to the more rigorous disciplines of computer science, like OS design.

Progress with Error Handling for BGP

              · · ·

It's been quite a while since I updated this blog, very lax of me, sorry! The lack of updates appears more indicative of how busy I appear to have been since presenting the error handling draft work at NANOG (which looks to be the last post!). Since January, I've presented at the IETF in Prague, and then again in Qu�bec City - particularly on a number of aspects of the work that I've been documenting here for some time!

NANOG 51 Presentation

              · · · · · ·

The video from the presentation I gave a NANOG, LINX and UKNOF has now been posted. You can find the video at the following URL - NANOG 51: BGP Error Handling or by clicking on the image below. The full slide deck is also on this site - here.