Marilag Ang Malaya

Thursday, October 29, 2009

My opinions and reactions on the class DPI project

Repost from my CS 259 class blog.

When we first started the class DPI project, the first thing that came into my mind was how easy it would be. I mean, how difficult would it be to open packets, inspect their contents, and classify them accordingly. You could say it would be the equivalent of your friendly postman opening your mail, and classifying whether it contained something important, a postcard, some cash, or perhaps spam and even anthrax. And we're not looking for passwords, credit card information or information for the spooks. No, we are more benevolent than that.

Our purpose would be to classify applications running on the network properly. If we're going to monitor our networks, we must have a complete picture of the applications that our users are running on them. While most of these applications are "visible" and can easily be blocked. However, many applications running on the Internet have acquired the ability to bypass firewalls and proxies. Because of many corporate, academic, technical and what-not policies that have governed networks for the past few years, have pushed applications to use proxies or encrypt their communications in order to bypass the usual roadblocks that network administrators have put in place over our networks today.

The wisdom of such blocks have been in serious question, both on the technical and user levels. However, the reality is that these blocks are here to stay, and the target applications of such blocks have adapted to the current Internet landscape. A great example of such a versatile program would be Skype.

The purpose of our class project was to detect peer-to-peer traffic that have managed to pass through the roadblocks that the university network administrators have put in place.

While we did manage to get a sample of the network traces, we have yet to detect any peer-to-peer activity in the university network. So far, the university network administrators have appeared to succeed in their "quest" to block all kinds of peer-to-peer traffic.

We also used some machine learning techniques on the traces, however, I think that we have largely failed in that because we don't have any training data to use... because there have been no peer-to-peer traffic detected. We need to get data which we positively know has peer-to-peer traffic. If we can't detect it, then we should run some applications and actively look for holes in the university network. Once we "detect" our own traces, put them into the machine learning tool and use it as training data to detect the peer-to-peer traffic that do not belong to us.

The other technique that the class investigated, which is actually reading the packet contents, is either a hit-or-miss thing. We can argue that reading the first few bytes of the data can give us the name of the actual application, however, once this traffic is encrypted, all bets are off. I believe this technique will only be useful in the near-to-medium term, and will work only on simple applications that have not acquired the variety of users who need to use special methods to bypass proxies and firewalls.

We are not yet there, but we have learned the "what not to do in DPI". This may sound like an Edisonian way of thinking, but I believe that as we continue to refine our techniques and code, we will be able to achieve a way to detect peer-to-peer traffic without reading the payload.

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Thursday, October 15, 2009

A first look at Google Wave

I have received my Google Wave invitation yesterday morning. I immediate took to inviting some more people to join me in testing Google Wave.
So far, it's been very very exclusive, and I only have 5 contacts on my list, not really many, and it really makes it difficult to test. However, that really doesn't stop us, does it? =P
The Google Wave team has been working very fast on this one. Some bugs that I saw yesterday were already gone today. For example, when you make a new wave and then change your mind so you want to discard it, yesterday you have to click on Trash to delete it. That has been fixed to today.
Wave really looks great towards the future of online collaboration, including a great way to finally do online meetings.
Kudos to Google for a job well done on Wave! ^_^
in reference to: Google Wave API | Google Groups (view on Google Sidewiki)

New Twitter background

I've always wanted to personalize my Twitter page, and so I made an initial attempt. The symbol that you see on the left is the symbol for "section". I wanted to put a 9 in there somewhere so that it would read as "Section 9", like the agency from Ghost in the Shell. But I think it looks better without the 9. What do you think?

in reference to: Twitter / Home (view on Google Sidewiki)

Tuesday, October 6, 2009

Freaky Fortnight at Slate

Watch as husband and wife switch places.

Freaky Fortnight 2009

Thursday, October 1, 2009

Advice from an experienced flood victim

By Gwendolyn So
(Reprinted from email)

Unbeknownst to many, my family and I are experts when it comes to flooding. By this I mean that for almost 10 years when we lived in a low part of Sto. Domingo Street in Quezon City , we experienced flooding INSIDE the house at least once a year and if I remember correctly, sometimes it was twice or even thrice a year.

The first time it happened we were in shock, but as it happened more and more it became routine. Here are some nuggets of wisdom that may help:

  1. I learned that once the water reaches knee level, the gates can't be opened anymore because of the water pressure. We thought we still had time to take the cars out but realized we were trapped. That time our cars submerged. Make sure you know which area near your residence is considered higher ground and take your cars there EARLY.
  2. Do not despair so much if your cars submerge. They can be fixed. It's expensive and takes a long time for the smell to go away, but it's not the end of the world. After the flood, just let the car dry. We were still able to use our Hi-Ace and Mitsubishi Lancer despite their having been half submerged in floodwaters.
  3. I learned that heavy stuff, like the ref and shelves, FLOAT. So every year from then on, we would TIE DOWN heavy appliances like the ref (too heavy to carry upstairs but in latter years we did lug it all the way up to the 2nd floor), the big shelves with wedding souvenirs and knick knacks and my dad's collection of wine. How did we do that? Tie them to the windows.
  4. Adrenalin will give you superpowers once you decide you're not afraid of a little water and start saving what you can. In my case, it was my collection of books. They're not rare first editions but regular books. However, I love my books and I'm not letting them drown! I was able to move and carry our heavy sofa powered by my body's own adrenalin hormone.
  5. You can have fun in the midst of disaster so I took out our cameras and starting taking pictures. It was to make everyone have a good laugh as we surveyed the chaos around us, the cockroaches and rats swimming by, the black inky spots of oily stuff occasionally floating around.
  6. Apparently, no matter how much you're enjoying yourself frolicking in the water and saving what you can, once the cold water reaches your chest (especially your nipples), you start to shiver and it gets hard to breathe. This is the time to give up and go upstairs.
  7. If your electricity stays on, go to the switch box and turn off all the electric outlets downstairs but not upstairs.
  8. Cleaning after the flood is a pain. Once the waters recede, you are left with mud everywhere. They stick so you have to get the hose and start using the walis tingting (how do you say this in English? It's a broom made of just think twigs/sticks tied together in a thick bundle). You just keep the water running and sweep, sweep, sweep like there's no tomorrow.
  9. You must scrub the walls with disinfectant. If you only rinse with water, it will still smell. We used Lysol. Scrub, scrub, scrub like there's no tomorrow. (If Lysol is too expensive, just try the regular bleach!)
  10. First time water got inside our house, we didn't know we had to use Lysol and that the drying process is super vital. So, after a few days, there was this nauseating smell and later we found molds growing everywhere! We had returned the furniture and appliances to their normal places and the walls behind grew molds. Yuck!!!
  11. We were still able to use our ref that floated in flood waters. Just clean and clean and dry and dry.
  12. Once electricity is available, get out all your fans and dry everything thoroughly.
  13. Yes, paint will peel off and wooden drawers and shelves deform. Salvage what can be used. Once they dry, it's still ok but sometimes the drawers get stuck because the wood expanded so you have no choice but to destroy it because icky water is still trapped inside.
  14. Wait at least 2 to 3 days to dry everything. Use fans and hairdryers. Do not, I repeat, do not be in a hurry to return stuff you saved to their original places.
  15. Have this mindset: Ah, it's good I'm now forced to do a general cleaning of my house. Now I have no choice but to do it. advice from me...
It is easy to go insane after this kind of calamity, to despair of the material things we lost (especially the cars), but please be thankful you got away with your life and that of your family and loved ones. Just keep on smiling. "Smile and whole world will smile with you; weep and you weep alone!"