Benjamin Chodroff

It’s been awhile, so here is the quick update:

• I graduated from Case this semester with my B.S. in Computer Engineering and will return to defend my Masters thesis in March
• I moved downtown into the Bradley Building on West 6^th in Cleveland with Eric Pinzur, a friend and fellow Case and Phikap alumnus – come visit us!
• I start work at IBM here in Cleveland, OH doing technical sales on January 28^th
• I’m heading to Munich and then to Prague to go skiing with the family and visit my sister, Eleanor, who is studying in the Czech Republic

Expect plenty of new pictures and, who knows, maybe some more blog posts. Maybe.

I needed a list of websites of all the Fortune 500 from 2007 for my masters project. Unfortunately, Fortune wanted to charge me hundreds of dollars to get some fancy excel spreadsheet with much more information than I really needed. I suspect there are other people out there who might find this list useful, so I’ll share how I made it (in case you want more than the URLs). However, you can skip all the following and just download The 2007 Fortune 1000 Website List. Also, here is a zip file of the 2007 Fortune 1000 HTML files found at money.cnn.com.

Using wget, you can download each of the 1000 . The URL links seem to be slighly random, but they are found between 1.html and 5000.html. Thankfully, wget just ignores saving 404 error pages. So, we download all the links in an empty directory:

• for i in `seq 1 5000`; do wget http://money.cnn.com/magazines/fortune/fortune500/2007/snapshots/$i.html ; done

Ah, that’s nice - we somehow have some extras. After some analysis, this will fix the problem:

• for i in `fgrep xxxxx *|awk ‘{ print $1 }’|awk -F “:” ‘{ print $1 }’|sort|uniq`;do rm $i;done

Woohoo! 1000 html files - perfect!

• cat *.html|grep Website|grep headersmtext|awk ‘{print $4}’|awk -F “\”" ‘{ print $2 }’|sort|uniq > output.txt

Oddly, you’ll only end up with 996 unique urls because the following are duplicates (which is correct):

• http://www.cvscaremark.com
• http://www.fcx.com
• http://www.integrysgroup.com
• http://www.oshkoshtruckcorporation.com

Part of my masters project work involves using network measurement tools to garner information about a path to a website. One useful type of tool that I don’t believe is used that often is a bandwidth estimation tool. These type of tools employ one of a variety of methods to estimate the available bandwidth between each TTL hop along a given router path to a host. To learn more about these tools, including clink, I recommend reading “Creating a Bandwidth Estimation Testbed Summer 2001 Status Report.”
One of these tools, Clink, was written by Allen Downey and has made significant improvements to Van Jaconbson’s similar tool, pathchar. Unfortunately, I noticed a problem where clink seemed to hang on certain hosts. I don’t believe I am alone in reporting this problem. In, “Measuring Bandwidth between PlanetLab Nodes” (PDF Link) as published in the proceedings of PAM 2005 – Passive & Active Measurement Workshop, the researchers noticed that clink would hang on PlanetLab’s machines and attributed the hang to a possible Linux kernel version problem. It is possible the kernel is the case, but I ran into another situation where clink would experience what looked like a program hang and might explain their hang as well.

When clink experiences a timeout on a probe to a TTL hop, it simply retries the probe again. Of course, if the router has been setup to not respond to UDP packets as many routers in todays internet are now setup to do, clink will endlessly try probing the router with no success. To the end user, this looks like a hang, but a tcpdump will confirm clink is still firing off the same UDP packet probe over and over. When clink was written in 1998-99, many routers were configured to (nicely) respond to a probe, but this is not the case any more.

Because I found clink’s bandwidth estimation using the even-odd technique even-odd technique, as described in the SIGCOMM paper, to be the best available, I rewrote part of the code to fix the infinite loop bug caused by router timeouts. I introduced two new program arguments. The first is a maximum probe retry value and the second being a maximum probe failures per TTL hop. Therefore, you could retry a probe of a specific size against a specific TTL hop multiple times using the first argument before declaring the probe a failure. Then, if the number of probe failures on a specific TTL hop exceed the second argument, the TTL hop is simply indicated as failed and is skipped. Clink then goes on to measure the rest of the hops.

I am not publishing the code patches yet as I am still testing it, but if you are interested in taking a peak at it, please comment and I’ll email you a copy.

After spending four months in India, London was a night and day difference. The air was not clean but rather was filled with the scent of western cologne. I can’t say I enjoyed it any more than the dung and garbage lots I found in India, but at least this scent was sanitary. In fact, sanitation was really a novelty to me. The hotel I stayed at with my parents was…spotless. Of course, at the price I was paying, one could nearly construct a new hotel India (no, but it really is expensive).  The cab ride from the airport to the hotel alone was over 60 times more expensive than in India. It just blew my mind.

Once you get past the price, London is just like any other city. We went shopping, saw Spamalot (hilarious), and did the usual tourists attractions. I really enjoyed the British Museum and our day trips out to see Stonehenge, Bath, Oxford, and Stratford. I spent the week catching up on all the sleep I had lost as well as soaking in the luxeries I had nearly forgotten about. These included constant electricity, fast internet, temperature controlled rooms, hot showers with shower heads, toilet paper (oh, how I missed it), clean clothes, and mattresses with clean sheets. To be honest, all of these luxuries are possible and certainly cheaper in India, but were out of my price range while trying to live off of my Indian salary. That last part is the key difference.

And, while I have left out many stories, that concluded my summer. I am now back in Cleveland toiling endlessly away on my masters project during my last semester. I act like life is hard, but I know it isn’t. I have embraced the lifestyle I all but abandoned while in India, but certain things have remained. I have been cooking a lot more Indian dishes now that I know how they are supposed to taste. I notice Indian people a lot more (and I sometimes will interject a “shukriya” in conversation to see if they notice). I am applying to full time positions, but otherwise, life is quiet and a bit lonely. Alvida, summer.

My friends at IBM India helped me put together my travel itinerary for the rest of my trip in India. They all agreed on one thing - there is no place more beautiful than Kashmir, but going there might be the last thing I’ll ever do. Kashmir has a long history of violence and unrest. What was once the jewel of India has now been marred by constant bomb explosions and killings.

Nonetheless, this is my only trip to India. I decided to toss the advice given by my friends, The Lonely Planet tour book, and others aside. Foolish? Yes, but I wasn’t going to regret it and I booked a trip.

Flying into Srinagar is like flying into a military compound. Granted, the weekend I flew in was India’s Independence weekend, so the troops were out in full force. There were over 700,000 troops on the ground and were literally spaced at least one soldier for every 10 meters on most roads. Vehicle checkpoints are positioned throughout the city and cars are inspected at gunpoint. Once you get out of Srinagar, things get a little less scary, but the troops are still around no matter how far into the countryside you go.

I stayed in a houseboat on Dal Lake. I had beautiful accommodations and the food was among the best I had tasted in all of India. I took trips to see Gulmarg and Sonamarg mountains. The Mogul Gardens were also very pretty and I enjoyed the boat rides through the floating vegetable gardens. While in Kashmir, I purchased a kilo of tea as it was the best tea I have ever tasted. The secret is to boil the tea leaves with cardamom pods, cinnamon stick, and saffron, which I also purchased. Kashmir’s rugs are known as the best in the world and I bought a few as presents and a personal souvenir.

As much as I would like to, I can’t recommend any one going to Srinagar. However, if you do go, you will have a great time and see some beautiful sites you just won’t see anywhere else in India. It is a personal decision that every person will have to make themselves. I spoke at lengths with the residents about the situation and it is clear that if one thing can fix Kashmir, it is more tourism and independence. Their situation is better off with India than with Pakistan, that to me is clear. However, India is not treating Kashmir with the respect it deserves and I would have to agree that Kashmir might be best as its own country. Then again, I am not a very political person and there is really no reason that Kashmir should not be able to function within India. India has worlds of opportunities and Kashmir could only benefit from these if India were to loosen the military control it has placed on Kashmir.