Conference Call: a Project is Going Awry

Somewhere, today, an IT project is quietly going awry.  Or, perhaps it is going awry not so quietly, thanks to that bane of open-office workers, the speakerphone.

Some time ago, I was sharing a room with about forty people working on a number of projects. One day, a conference call got underway with two or three people and a speakerphone. I was too far away to hear what the local people were saying, but the voice on the phone was loud and clear throughout the office. The call went roughly like this:

Speakerphone: [volume is pumped up to the max] … everyone’s here? Great, how are we doing today?

Local team: [indistinct talking]

Speakerphone: Are we still on track to deliver the code to the testers next Friday?

Local team: [indistinct talking]

Speakerphone: So are you saying we’ll miss this date?

Local team: [indistinct talking]

Speakerphone: So why are we slipping the schedule yet again?

Local team: [longer indistinct talking]

Speakerphone: You know guys, it’s gotten to the point that when I hear another one of your excuses it sounds like fingernails being dragged across a chalkboard. I don’t understand what … [becomes indistinct as volume is rapidly pumped down]

I didn’t overhear any further conference calls from that area. I don’t know if that’s because the team got smart about speakerphone etiquette or because the project got canceled.

Giveaway Calculators Then and Now

In my previous post, I described how to calculate a cube root on an ordinary calculator. Ordinary calculators are so inexpensive that they are given away as promotional knick-knacks. Here is one I received a few years ago at a university’s Campus Day – it’s not only a calculator, it’s also a ruler with inches and centimetres:

Now you might think that giveaway calculators first appeared around 1990 when advances in integrated circuits brought down the cost of a calculator microprocessor to less than a dollar. And you would be wrong. Here is a giveaway calculator from the 1950s, over half a century ago:

Like its modern counterpart, it’s not only a calculator, it’s also a ruler with inches and centimetres. Like the digital calculator above, it is shown just after someone worked out the cube root of 10 – and quickly too. Slide the cursor (the window) so that the red line is over the 10 on the K scale, then see the answer on the D scale directly above – 2.15 – accurate to three digits. What the digital calculator loses in speed (because you have to poke all those buttons), it makes up in accuracy (with an extra four or five digits of precision).

Back of giveaway slide rule calculator.

One difference between then and now: lots of people use digital calculators today, but analog calculators were mainly aimed at tech-heads like engineers — this one even came with a soft plastic case perfect for engineers’ shirt pockets.

Calculate 2π. Line up 1 on the C scale to π on the D scale. Now, 2 on C lines up with the answer on D: 6.28. Bonus: follow the red line to the A scale for 2π squared, 39.5.

The Internet is Born, Thanks to Cats

From ARPANET to Internet

It is well known that the internet, that indispensable part of modern civilian life, started out as a US Department of Defence project to build a robust computer network, the ARPANET. I sometimes wonder what the military leaders of that era would think if they can see what their project has grown into. How would a general of the 1960s react to seeing people using this technology, designed for better warfare, to watch videos of cats doing wacky things?

In my mind I imagine that there was a fateful meeting that set the direction. In the 1960s, computer networks are emerging from research labs into productive applications, but they are not fault-tolerant. The military is interested, but the it needs networks that can survive attacks, and university labs think they have the answer. A meeting is convened at the Pentagon where university professors can present their ideas for a new kind of network.

The Professors have a Proposal

As a general and other military staff listen, the professors explain how networks of the day look like trees with branches, nodes, and leaves. This design is easy to build and run thanks to minimal links and simple route planning, but it has a problem: if any branch is cut then the network breaks into two parts.

A tree is the simplest kind of network …

… but any single failure breaks it.

The professors want to build a network that looks more like a highway system, where there are several routes between any two places. If a road is blocked, those multiple routes mean network remains largely intact.

Loops in this network make it more complicated to build and operate…

… but it tolerates failure points.

Of course every benefit comes with a price, and with this road-map-style computer network the price is in the computers at the nodes of the network. When forwarding a packet of data toward its destination, a node has to choose between several outbound links. The choice depends not only on the direction to the destination, but on the capacity of each link and data-traffic congestion.

The computer in each nodes of the network requires more complex algorithms and more processing power than was current in the industry-standard tree-networks.

As the presentation progresses, the military staff are becoming more and more enthusiastic with what they are hearing, and by the end, they are sold on this project.

It is at this point a staff member stands up to say “Your proposal is very impressive, and I think I speak for all of us in saying we would like to move forward. What would be our the next step?”. The professors are ready with a plan to build a prototype network that links together several universities and military bases. The general asks, “Can you estimate how much your prototype network will cost?”. One professor stands up, and begins by listing a number of caveats – “great complexity”, “untested algorithms”, etc. – before finally stating a price. A very high price.