WISP Design: Using OSPF to build a transit fabric over unequal links
Defining the problem – unused capacity
One of the single greatest challenges if you have ever owned, operated or designed a WISP (Wireless Internet Service Provider) is using all of the available bandwidth across multiple PtP links in the network. It is very common for two towers to have multiple RF PtP (Point-to-Point) links between them and run at different speeds. It is not unusual to have a primary link that runs at near-gigabit speeds and a backup link that may range anywhere from 50 Mbps to a few hundred Mbps.
This provides a pretty clean HA routing architecture, but it leaves capacity in the network unused until there is a failure. One of the headaches WISP designers always face is how to manage and engineer traffic for sub-rate ethernet links – essentially links that can’t deliver as much throughput as the physical link to the router or switch. In the fiber world, this is pretty straightforward as two links between any two points can be the exact same speed and either be channeled together with LACP or rely on ECMP with OSPF or BGP.
However, in the WISP world, this becomes problematic, as the links are unequal and Continue reading
Nokia Hit With Q3 Net Loss as Network Buildouts Slow
About that $17B Alcatel-Lucent buy — why didn't that help?
Designer or Architect? It’s A Matter Of Choice
I had a great time at ONUG this past week. I got to hear a lot of great presentations from some great people, and I got a chance to catch up with some friends as well. One of those was Pete Lumbis (@PeteCCDE) who had a great presentation this past spring at Interop. We talked a lot about tech and networking, but one topic he brought up that made me stop and think for a moment was the wide gulf between design and architecture.
Binary Designers
Design is a critical part of an IT project. Things must fit and make sense before the implementors can figure out how to put the pieces together. Design is all about building a list of products and describing how they’ll interact once turned on. Proper design requires you to step away from the keyboard for a moment and think about a bigger picture than just hacking CLI commands or Python code to make some lights start blinking in the right order.
But design is inherently limited. Think about the last design you did, whether it be wireless or networking or even storage. When you start a design, you automatically make assumptions about Continue reading
Reaction: Keith’s Law
Ethan pointed me to this post about complexity and incremental improvement in a slack message. There are some interesting things here, leading me in a number of different directions, that might be worth your reading time. The post begins with an explanation of what the author calls “Keith’s law”—
The author attributes this to the property of emergence; given I don’t believe in blind emergence, I would attribute this effect to the combined intertwining of many intelligent actors producing an effect that at least many of them probably wanted (the improvement of the complex system), and each of them working in their own spheres to achieve that result without realizing the overall multiplier effect of their individual actions. If that was too long and complicated, perhaps this is shorter and better—
The law of Continue reading