Reaction: Science and Engineering

6 December 2017 | Comments Off on Reaction: Science and Engineering

Are you a scientist, or an engineer? This question does not seem to occur to most engineers, but it does seem science has “taken the lead role” in recent history, with engineers being sometimes (or perhaps often) seen as “the folks who figure out how to make use of what scientists are discovering.” There are…

Thoughts on Open/R

21 November 2017 | Comments Off on Thoughts on Open/R

Since Facebook has released their Open/R routing platform, there has been a lot of chatter around whether or not it will be a commercial success, whether or not every hyperscaler should use the protocol, whether or not this obsoletes everything in routing before this day in history, etc., etc. I will begin with a single…

A glance back at the looking glass: Will IP really take over the world?

6 November 2017 | Comments Off on A glance back at the looking glass: Will IP really take over the world?

In 2003, the world of network engineering was far different than it is today. For instance, EIGRP was still being implemented on the basis of its ability to support multi-protocol routing. SONET, and other optical technologies, were just starting to come into their own, and all optical switching was just beginning to be considered for…

Applying Software Agility to Network Design

30 October 2017 |

The paper we are looking at in this post is tangential to the world of network engineering, rather than being directly targeted at network engineering. The thesis of On Understanding Software Agility—A Social Complexity Point of View, is that at least some elements of software development are a wicked problem, and hence need to be…

Random Thoughts on Grey Failures and Scale

17 July 2017 | Comments Off on Random Thoughts on Grey Failures and Scale

I have used the example of increasing paths to the point where the control plane converges more slowly, impacting convergence, hence increasing the Mean Time to Repair, to show that too much redundancy can actually reduce overall network availability. Many engineers I’ve talked to balk at this idea, because it seems hard to believe that…

Anycast and Latency

30 May 2017 | Comments Off on Anycast and Latency

One of the things I hear from time to time is how smaller Internet facing service deployments, with just a few instances, cannot really benefit from anycast. Particularly in the active-active data center use case, where customers can connect to one data center or another, the cost of advertising the service as an anycast, and…

Network Slices

23 May 2017 | Comments Off on Network Slices

There has been a lot of chatter recently in the 5G wireless world about network slices. A draft was recently published in the IETF on network slices—draft-gdmb-netslices-intro-and-ps-02. But what, precisely, is a network slice? Perhaps it is better to begin with a concept most network engineers already know (and love)—a virtual topology. A virtual topology…

MegaSwitch: an interesting new data center fabric

25 April 2017 |

Data center fabrics are built today using spine and leaf fabrics, lots of fiber, and a lot of routers. There has been a lot of research in all-optical solutions to replace current designs with something different; MegaSwitch is a recent paper that illustrates the research, and potentially a future trend, in data center design. The…

Don’t Leave Features Lying Around

27 March 2017 | Comments Off on Don’t Leave Features Lying Around

Many years ago, when multicast was still a “thing” everyone expected to spread throughout the Internet itself, a lot of work went into specifying not only IP multicast control planes, but also IP multicast control planes for interdomain use (between autonomous systems). BGP was modified to support IP multicast, for instance, in order to connect…

Into the Gray Zone: Considering Active Defense

28 February 2017 | Comments Off on Into the Gray Zone: Considering Active Defense

[time-span] Most engineers focus on purely technical mechanisms for defending against various kinds of cyber attacks, including “the old magic bullet,” the firewall. The game of cannons and walls is over, however, and the cannons have won; those who depend on walls are in for a shocking future. What is the proper response, then? What…