VIDEO: P And he's got your address.
Warriors of the net.
Right so coming soon is how the internet works.
And it's not
DAVID MALAN: Coming soon 15 years ago.
I've always had misgivings with that video.
I love it.
And the team at Ericsson, I think at the time,
was really pushing the envelope with some graphics work.
But it takes some liberties with accuracy.
Uses some terms that even I haven't heard.
But it does actually paint a nice visual picture
of some of what goes on underneath the hood in the internet.
DOUG LLOYD: Right.
It can be a pretty abstract concept.
So even to have some idea, even if it's an imperfect
one, of how the internet works is good.
DAVID MALAN: And we actually spend a decent amount of time
in this lecture on how the internet works and how home networking works.
And in fact, that's what the picture was that was on the screen there.
I think that was a sample page from a routers documentation online.
And it's a nice opportunity, I think, to remind students of the very topology
that they have at home.
Probably some Wi-Fi reception in their home, apartment, in their dorm room,
or office.
And to start to peel back those layers and explain how it works.
DOUG LLOYD: Have you ever considered a pset that touches on is?
So last year, we did server which vaguely touches on HTTP.
Which is what we're starting to talk about here.
But this year, we didn't actually have a problem set during this week.
This was during the week of our first midterm.
DAVID MALAN: We moved things around.
I mean, for me, I like the societal relevance here.
I think this ties in very well to our new CS50 AP initiative.
Where it shows the intersection of technology and society.
But for me, the functional role of this material beyond just
being enlightening, and I think good for everyone to know in the real world.
Is that it really sets the stage for a look at web programming later on.
And it allows us to broaden the canvas of opportunities for students
to program and solve problems on.
Now to programming for the web or for mobile devices and the like.
And I think understanding those basic implementation details is compelling.
Especially when we start talking about protocols.
Like HTTP and explaining how HTTP supports cookies and with cookies can
you get sessions.
And so, we can continue our discussion of abstraction and layering more
and more sophisticated functionality on top of lower level implementation
details.
DOUG LLOYD: This really sets the stage for what's to come in the future weeks.
DAVID MALAN: Indeed And I think you never have a more attentive audience
or student body than when you're talking about things
that are so relevant to them.
And understanding how messages are being transmitted
from their phone to another phone, or through the airwaves in a room
and so forth.
And what kind of threats you expose yourself to by using insecure Wi-Fi,
or by using a weak password.
In fact, we'll continue this discussion of security
later on when we look at SQL, databases, and how you can accidentally
render yourself vulnerable.
Early in the semester we talked about buffer overflow exploits
in the context of C and memory management.
So there's a lot of opportunities, I think,
to discuss throughout the arc of a CS course.
Some real world security privacy issues as well.
And that just motivates an understanding of this all the more.
So that even if you are threatened every day in some form technologically,
at least you can weigh the risks against the benefits
of using these various technologies and decide for yourself.
As opposed to being ignorant completely to what attacks you might suffer.
DOUG LLOYD: No, that's a great point.