Address Space

One of the problems faced by the designers of the Internet was the ability for computers to find one another. If a global network of computers were to function in a decentralized way, there needed to be a way for any computer to send information to any other. An address scheme was created in the late 1970s called Internet Protocol. With this system, each computer on the Internet is given a unique address, called an IP address. This address is a 32 bit number, divided into four octets. Each octet narrows the location further, allowing traffic to be efficiently routed between any two computers.
Usually, the octets are written as a sequence of four numbers, each ranging from 0-255. For example, was the server at Miami where Mrs. Schinker and I met. Our web server at school is Theoretically, there are about 4 billion of these addresses, making it possible for the Internet to route traffic among 4 billion computers.

In 1983, when this system first started seeing wide adoption, this was plenty. There were about two million computers in the United States, and almost none of them were connected to this network. At that time, there were about 4 billion people on the planet. The idea that every person on earth would have a computer on this network was inconceivable.

These days, of course, that 4 billion number is looking smaller and smaller. With more cell phones on the planet than people, some estimates indicate that there are as many as 9 billion devices online now. We exhausted that 4 billion address space a long time ago. The thing that has kept the Internet from grinding to a halt for the last decade is a workaround called “network address translation” (NAT). If you compare an IP address to the street addresses we’re all familiar with, then NAT is like assigning apartment numbers. In this online city, though, almost every building is a high-rise apartment.

Take, for example, my school district. We have about 6,000 devices in our schools, almost all of which are connected to the Internet. But because we use NAT, every computer appears to use the same IP address, So, from the Internet’s perspective, it just treats our whole school district as one computer. That’s how we can get 9 billion devices with only 4 billion addresses. But that only goes so far. At some point, we are going to need more addresses.

The smart people who keep the Internet working saw this problem coming twenty years ago. They created a new address scheme, called IPv6, which uses 128 bits instead of 32. That means there are 340 undecillion possible addresses. That’s 3.4 x 10^38 addresses.

The bad news is that much of the current Internet still doesn’t support IPV6. Android devices have a lot of problems. Mac OSX 10.7 – 10.10 tries not to use it. Windows didn’t support it until Vista. Cisco switches didn’t support it until version 15. Hardware manufacturers were slow to adopt it because nobody was using it. Nobody was using it because, well, no devices supported it.

But the time has come. With no more old addresses available, we have to transition. It’s going to be painful and expensive. It’s going to take a lot of time. Hopefully, most people won’t even notice.


The good news is that we will only ever have to do this once. The new system has plenty of addresses. 340 undecillion is a really big number. It’s enough to give everyone on the planet their own private Internet without even scratching the surface. It’s enough for every grain of sand on earth to have as many addresses are there are grains of sand on the earth. If the old address scheme supported an Internet the size of a golf ball, the new one would be the size of the sun. If every atom on the surface of the Earth had an address, there would be enough left over for 100 more planets. I think you get the point. There are lots of addresses.

I can’t imagine a world where we could ever possibly use that many. Just like they couldn’t in 1983.

Photo credit: Penn State University



A More Perfect History

Last week, the College Board released a new version of the AP U.S. History Course and Exam Description. This document, last revised in 2014, outlines the content that should constitute an Advanced Placement American History course. Ideally, students taking this course pass the exam at the end of the year that entitles them to college credit for their achievement.

7522707282_46e00dc43e_zThe United States does not have a national curriculum for American History. The Common Core standards, an effort to unify the curriculum taught in American schools, only cover reading and math. The AP guidelines are the closest thing we have to a national standard for how this subject should be approached in high school.

The new standards come a year after strong opposition to the 2014 version. That revision emphasized comprehension, interpretation , and synthesis of history instead of merely recalling the names and dates of important milestones. Critics claimed that it undermined the idea of American exceptionalism, and fostered a view of American history that is too negative and political. Several states moved to ban the course from being taught in their schools.

In academic circles, we call this shift toward analysis, synthesis, and application an increase in academic rigor. As we continue to move into the age of information abundance, it becomes increasingly important for students to evaluate the information they’re getting, make connections among content from diverse sources, assess bias and frame of reference, and draw their own conclusions. They apply this deeper understanding  of history in new contexts, ostensibly to keep from repeating it.

Unfortunately, some of those conclusions don’t necessarily paint the United States in a positive light. After looking at the facts, one might conclude, for example, that the Boston Tea Party was actually an act of terrorism. Or, maybe, the strained relations between Europeans and native tribes had more to do with the Europeans dismissing them as savages, taking and destroying their resources, and constantly breaking treaties than with the natives acting unreasonably hostile toward white settlers. It’s quite possible that rounding up Japanese Americans, most of whom were United States citizens, and locking them up in interment camps after confiscating their homes and property was a heinous violation of their civil and human rights. One might conclude that detaining 780 people in the aftermath of 9/11 without charge or trial, and then systematically torturing them  over the course of a decade poses a stark contrast to the certain inalienable rights endowed to them by their creator.

Fortunately, the new version of the course re-instills those patriotic American ideals that make our citizens believe that this is the greatest country in the history of the world. Our nation is founded on the ideals of liberty, citizenship, and self-governance. Just don’t get too caught up in that definition of “liberty,” and be careful about that “self-governance” thing if you’re black or female or poor. George Washington, Benjamin Franklin, and Thomas Jefferson are fearless leaders to be revered, and have more than earned their places on our currency. Let’s set aside Washington’s blundering that would have lost the revolutionary war if the French hadn’t conveniently saved the day, Franklin’s inability to keep his hands to himself, and Jefferson’s substantial bi-racial posterity. The Declaration of Independence and the Constitution should be revered as sacred documents, unless you take that bit about being created equal too seriously, or unless the unelected Supreme Court issues a ruling you don’t agree with. We were certainly the determining factors in ending both world wars, and the U.S. is the only country who realized that the cold war could be ended by simply telling Mr. Gorbachev to “tear down this wall.” Let’s conveniently omit the fact that the United States, 70 years later, is still the only country to have actually used a nuclear weapon. Don’t get too caught up in the details. We’re awesome, and we know it.

A generation ago, I took this AP American History course. We skipped most of the dates and facts. The textbook spent most of the year in the bottom of my locker. The units focused on essential questions that were primarily answered through the examination of primary sources. We learned to interpret history for ourselves. We learned to assess bias. We learned about different kinds of oral and written accounts, and how to determine why they were created, by whom, and when. One of the units focused on the cause of the civil war. Slavery was a contributing factor. But it wasn’t the only factor, and it probably wasn’t the driving force. Slavery as a human rights issue was certainly not as important as slavery as an economic issue. But we didn’t blindly read an over-processed, committee-driven, negotiated account in a textbook about why there was a civil war. We explored the topic ourselves.

We didn’t cover most of the course. We glossed over almost all of the dates and names. I don’t think the teacher was overly concerned with our exam scores. In fact, we didn’t have any assessments or grading at all, apart from the final exam. We were intrinsically motivated, and the subject was made interesting by the approach taken by the teacher. It was certainly a time before high-stakes accountability.

I scored well enough to earn six college credits and was exempted from taking Western Civilization as a college Freshman. I don’t remember much about the exam, except that in the essay, I argued that affirmative action programs were discriminatory. I’m pretty sure I criticized Lincoln in the same essay.

I love my country. There’s video and photos all over the Internet of me waving flags and singing patriotic songs. I know most of the words to the Pledge of Allegiance (even though I think it’s a really creepy nod to fascism). I sing the words to the Armed Forces Medley and Stars and Stripes Forever every time I hear them. But I think our country can be better. There’s lots of room for improvement. And we don’t get better by ignoring the inconvenient misdeeds of our past.  Our students need to study all of American history, not just the parts that make us look good. They need to draw conclusions, identify and acknowledge misdeeds, and resolve to prevent their leaders from walking down those same paths.

Maybe that’s what the critics are afraid of.



Sans Livres

Shortly after school ended in June, the custodial staff descended on the high school media center. They removed all of the books and bookshelves.

This2015-07-20 11.26.42 move had been coming for a while. Book circulation has been remarkably low for years. This year, the number of books checked out was smaller than the number of students in the school, averaging fewer than eight books per school day. Earlier in the spring, the media specialist had identified all of the books that had not been checked out since the library switched to an automated circulation system in the late 90s. She also weeded out all of the outdated books (we stopped updating the print encyclopedias in the early 2000s). To this, she added materials that had been purchased for specific projects or to meet individual requests for teachers’ units that are no longer used. When she was done weeding, she realized that all of the books that were left would fit in the space formerly used to store magazines. So the books were moved to the magazine room.

Before you start with the technology-bashing, nostalgic ranting about card catalogs, the necessity of the Dewey Decimal System, and Google’s systematic deconstruction of modern civilization, let me also point out that at the same time, the custodial crews also removed the 34 computers, as well as the islands they were on. Those islands were using about 40% of the space in the room.  While some of those computers will come back, they won’t be front-and-center anymore. As part of our ongoing “places to people” initiative, most of our students are using mobile technologies more and more, and the need for desktop computers tied to a specific location is waning. The computers that remain will be off in the corners of the room where the bookshelves used to be.

The reality is that the media center is the largest instructional space in the school. It’s the only room that will fit 100 people in a collaborative academic setting. Our students need to work together on projects. They need to have access to creative tools, but those tools don’t need to dominate their learning spaces. They need to make connections to other people, both within and beyond the school. They need to hone their communication skills, through writing, peer editing, presentations, multimedia, and other forms that I don’t really understand. They need a space to innovate.

Most of all, the school needs a space that is flexible. It has to allow for individual study as well as collaborative work. It needs comfortable spaces and task-oriented places designed for productivity. It needs to allow for conversations but still be quiet enough for people to get their work done.  The high school has spent a lot of time trying to get that right, and I’m anxious to see how it turns out.

And, while we mourn the loss of printed books, what do the students think of all this?

Sad, yes. They enjoy reading. And they like reading from actual books. But the use of books as information resources is largely outdated now. The books we read now are pleasure books. So instead of a high school (or university) library model, which features a lot of nonfiction and a small fiction section, maybe we need to go back to the public library (or elementary school library) model, where most of the collection is pleasure reading. My guess is that most of the books that are left after the great purge of 2015 are just that: books our students enjoy for their own sake.

And those books aren’t going anywhere.