Russ

Author Archives: Russ

Reaction: AT&T’s Paper on dNOS

The AT&T White Paper: What they get Right, what they get Wrong

AT&T recently published a paper on dNOS, an open, disaggregated, Network Operating System for any kind of hardware. They list three primary purposes for their effort at helping the networking industry build an open source dNOS:

  • To improve the rate of innovation and introduction of new features
  • To provide more flexibility in network design
  • To reduce costs where possible by taking advantage of purchasing “at scale”

How could disaggregation help with these three goals? The first of these, the rate of innovation, is really about packaging and perception, but we often forget that perception is a large part of innovation. If software developers always believe they must wait on the hardware, and hardware developers always feel like they must wait on the software, then the two teams develop an interlocking system that can slow down the pace at which either team can operate. One certain way to drive innovation is to break up such interconnected systems, allowing each one to use the features of the other in ways not originally intended, or drive the other team to create new features through competition. For instance, if the software team Continue reading

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 few fields where this seems closer to the truth than computing. Peter Denning has written an insightful article over at the ACM on this topic; a few reactions are in order.

Denning separates engineers from scientists by saying:

The first concerns the nature of their work. Engineers design and build technologies that serve useful purposes, whereas scientists search for laws explaining phenomena.

While this does seem like a useful starting point, I’m not at all certain the two fields can be cleanly separated in this way. The reality is there is probably a continuum starting from what might be called “meta-engineers,” those who’s primary goal is to implement a technology designed by someone else by mentally reverse engineering what this “someone else” has done, to the deeply focused “pure scientist,” who really does not care about the practical application, but is rather simply searching Continue reading

SLAAC and DHCPv6

When deploying IPv6, one of the fundamental questions the network engineer needs to ask is: DHCPv6, or SLAAC? As the argument between these two has reached almost political dimensions, perhaps a quick look at the positive and negative attributes of each solution are. Originally, the idea was that IPv6 addresses would be created using stateless configuration (SLAAC). The network parts of the address would be obtained by listening for a Router Advertisement (RA), and the host part would be built using a local (presumably unique) physical (MAC) address. In this way, a host can be connected to the network, and come up and run, without any manual configuration. Of course, there is still the problem of DNS—how should a host discover which server it should contact to resolve domain names? To resolve this part, the DHCPv6 protocol would be used. So in IPv6 configuration, as initially conceived, the information obtained from RA would be combined with DNS information from DHCPv6 to fully configure an IPv6 host when it is attached to the network.

There are several problems with this scheme, as you might expect. The most obvious is that most network operators do not want to deploy two protocols to Continue reading

1 72 73 74 75 76 162