Monday, October 6, 2008

Virus scanners

I'm in print and not quoted too badly in our local paper, the Notre Dame Observer .

Friday, August 8, 2008

Back from ICCCN 2008

Just got back from ICCCN 2008. Very nice conference although the Virgin Islands were certainly quite hot and humid. More highlights to come later in the week regarding the panel discussions / etc.

Tuesday, June 17, 2008


No wonder over-provisioning is the norm in the core of the network. Wow.

Per the text:

Cogent this morning is announcing new discounts for customers who commit to three-year contracts and for higher volume service provider customers. The new three-year price for Ethernet service is a flat $7 a megabit, a dollar less than the previous rate for contracts of two years or more. For service providers who buy Ethernet services at volumes between 100 megabits per second and a Gigabit, rates are as low as $6 per megabit for a three-year contract. Service providers who buy between one Gigabit and 10 gigabits will enjoy a three-year contract rate of $5 a meg, and those that consume a full 10 gigabit port can pay as little as $4 a meg on a three-year contract.

Monday, June 16, 2008

HD as a Natural DRM

I think my list of tasks is now finally approaching a manageable level hopefully giving a bit more time to post what should be at least weekly content. Up this week is our recent position paper on using the size of HD as a natural DRM. While the paper unfortunately did not make it into NSPW, the topic is interesting enough that we have converted it over to a technical report and wiki-fied it. If anyone has a good LaTeX to Wiki converter, please let me know.

The thrust of the paper is relatively simple, is the size of high definition content (30+ GB) sufficient to act as a natural DRM and deterrent to file sharing. Taking a cue from music sharing, WAV file sharing certainly existed but the content was fairly large and the bandwidth speeds for exceptionally bad at that time. With the emergence of the MP3, all of that changed making sharing much easier. In some sense, HD content follows a similar parallel in that it is an order of magnitude greater in terms of size versus DVD and two orders of magnitude greater than CD-focused content.

If one looks at the general dynamics of beginning the seed of a movie say via BitTorrent, a fully symmetric link would take roughly 40 minutes to grab a 30 GB Blu-Ray disc (12.5 MB/s net speed ignoring headers, assuming TCP kept the pipe full, ignoring the ramp up in congestion avoidance). Now, while I would love for 100 Mb/s symmetric bandwidth to rapidly grow in the US, I simply do not see that happening any time in the near term. Taking DSL and sharing cuts bandwidth down by a factor of 10 on the downstream and 100 on the upstream. While P2P helps with that sharing, the file still has to get distributed out past that initial seeder. Given that one probably does not want to hang out too long on a given torrent with pirated content (*AA actions) nor wants to pay the potential bandwidth costs (size caps via Time Warner), is anyone going to be all that keen to share pirated HD content?

Ah, but what about smaller content as several of the reviewers raised? Sure, feel free to DRM away but the premise of the paper is that for HD content, it doesn't add all that match. With the analog hole (for any content) and nearly every DRM mechanism being cracked shortly after release, why bother? Can disc copying occur then? Most definitely but it is more like copying the analog tape of old rather than the easy, quick file sharing of today. Is it easier to copy or just to loan a disc? My thinking is that the economics of sharing (size caps on the upstream) will be a far more effective deterrent at sharing than DRM will ever be. Moreover, as the paper mentions, it is in the interest of the ISPs to try to swat down the heavy tail or at least convert that heavy tail into a net economic gain. We've already seen this with the recent brouhaha over P2P throttling and as much as one would like the all you upload buffet to continue, those days are likely numbered at least for the near term. It is quite easy to pick out the heavy tail on the upload and keep the "good" netizens from being penalized (good as in profitable subscribers to an ISP).

Long story short, it is an interesting topic of discussion in general with regards to design. Interesting questions as well would be quantifying the total energy cost of HD DRM or comparing it to applying it on Folding@Home or SETI@Home (computations spent). Alternatively, could one embed multiple signatures from the source side (ala steganography) to assist with tracing the root of shared content (40 GB is a lot of space to hide stuff but can it be done fast on the production side)? At what point are speeds feasible where DRM might need to be imposed, i.e. what is the cutoff where DRM is necessary (if at all)?

Sunday, May 4, 2008

I still function....

Wow, long time since the blog has seen an honest to goodness post. I'll just make a mental note that teaching a second course, even if it is a boutique course, and serving on a few university level committees are an amazing time sink.

Anyway, a few interesting updates since the last time I posted:

INFOCOM TPC: Whoot! Finally made it in which was nice and just in time for the promotion and tenure package for the fall. Special thanks to the anonymous individuals who pulled me in :)

RIPPS Demo We did a slightly working of RIPPS (our work on detecting rogue wireless access points) at INFOCOM 2008. USB and Mac Mini's do not play that well together when you toss libpcap into the mix.

Travel, travel, travel Per the recommendations of Azer Bestavros, I did the first leg of my CAREER evangelization tour visiting Univ. of Connecticut, Boston University, MIT, and Univ. of Kentucky in a one week span. Plenty of wonderful feedback and comments on the two works presented (RIPPS and my CAREER work).

Now that the semester is almost winding down, my goal is to bring the inter-post time way, way down and to muse on our weekly papers. We tried an experiment of discussion topics and papers which did not fare nearly as well.

Friday, February 22, 2008

USB Flash Drive Characteristics

We recently had two papers accepted at the upcoming IEEE WoWMoM, one on loss sourcing in 802.11 (more info in a later post) and the other on USB flash drive performance characteristics with respect to read/write speeds and power consumption. The work itself was done in large part by one of my summer REU students which is very cool to see those results turn into a tangible research output.

The paper in itself was an outgrowth of discussions related to a DARPA WAND proposal from last year. While we weren't funded, we had proposed the usage of USB flash to provide a cheap and easy method for significant on-demand storage for our packet caching architecture. There were some discussions that the flash drives would be too expensive power-wise and we were at a loss to directly respond to that. Long story short, that led to the above REU project to pin down the energy costs and performance of the drives which would be a necessity if the grant got funded (it was not, unfortunately).

The net result was that our initial hypothesis was correct, i.e. the cost of the flash drive in terms of power was dwarfed by the cost of the wireless adapter itself, especially in a USB 1.1 setup that would have likely been in place. We were not entirely vindicated as we discovered that by in large, the flash drive itself would never enter a low power mode when not in use, i.e. the file system is in essence permanently mounted which in turn triggered periodic "Keep Alive" messages across the USB bus, never allowing the flash drive to enter suspend mode. The REU student did a nice job diving into the ugly innards of the Linux kernel USB module to hacking up a suspend API for some basic testing. While it did offer the option to manually force a suspend, the performance results that could certainly use some tweaking as it would be ill-suited for significant amounts of suspend/resume operations.

All in all, a neat project for a REU. We posted a Wiki form version of the original submission here if anyone would care to peruse it. The final camera version of the paper (accepted as a short paper) will be posted in the next month or so to the website and will be available on the same link. The USB flash profiling tool is also posted on-line available via the same link or the above direct link.

Finally, I am finally taking the plunge and starting a policy of putting reviews from accepted papers on-line when I can. The nice part is that it gives us a chance to do a minor rebuttal but also it gives some nice transparency to the review process which in my opinion is a very good thing. The review / response notes for the paper can be found here.

Tuesday, February 19, 2008

New Cisco Research Site

For those interested, Cisco has a new front-end for Cisco research.