Technology, Thoughts & Trinkets

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Tag: comcast

Choosing Winners with Deep Packet Inspection

I see a lot of the network neutrality discussion as one surrounding the conditions under which applications can, and cannot, be prevented from running. On one hand there are advocates who maintain that telecommunications providers – ISPs such as Bell, Comcast, and Virgin – shouldn’t be responsible for ‘picking winners and losers’ on the basis that consumers should make these choices. On the other hand, advocates for managed (read: functioning) networks insist that network operators have a duty and responsibility to fairly provision their networks in a way that doesn’t see one small group negatively impact the experiences of the larger consumer population. Deep Packet Inspection (DPI) has become a hot-button technology in light of the neutrality debates, given its potential to let ISPs determine what applications function ‘properly’ and which see their data rates delayed for purposes of network management. What is often missing in the network neutrality discussions is a comparison between the uses of DPI across jurisdictions and how these uses might impact ISPs’ abilities to prioritize or deprioritize particular forms of data traffic.

As part of an early bit of thinking on this, I want to direct our attention to Canada, the United States, and the United Kingdom to start framing how these jurisdictions are approaching the use of DPI. In the process, I will make the claim that Canada’s recent CRTC ruling on the use of the technology appears to be more and more progressive in light of recent decisions in the US and the likelihood of the UK’s Digital Economy Bill (DEB) becoming law. Up front I should note that while I think that Canada can be read as ‘progressive’ on the network neutrality front, this shouldn’t suggest that either the CRTC or parliament have done enough: further clarity into the practices of ISPs, additional insight into the technologies they use, and an ongoing discussion of traffic management systems are needed in Canada. Canadian communications increasingly pass through IP networks and as a result our communications infrastructure should be seen as important as defence, education, and health care, each of which are tied to their own critical infrastructures but connected to one another and enabled through digital communications systems. Digital infrastructures draw together the fibres connecting the Canadian people, Canadian business, and Canadian security, and we need to elevate the discussions about this infrastructure to make it a prominent part of the national agenda.

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Background to North American Politics of Deep Packet Inspection

crtc566The CRTC is listening to oral presentations concerning Canadian ISPs’ use of Deep Packet Inspection (DPI) appliances to throttle Canadians’ Internet traffic. Rather than talk about these presentations in any length, I thought that I’d step back a bit and try to outline some of the attention that DPI has received over the past few years. This should give people who are newly interested in the technology an appreciation for why DPI has become the focus of so much attention and provide paths to learn about the politics of DPI. This post is meant to be a fast overview, and only attends to the North American situation given that it’s what I’m most familiar with.

Massive surveillance of digital networks took off as an issue in 2005, when the New York Times published their first article on the NSA’s warrantless wiretapping operations. The concern about such surveillance brewed for years, but (in my eyes) really exploded as the public started to learn about the capacities of DPI technologies as potential tools for mass surveillance.

DPI has been garnering headlines in a major way in 2007, which has really been the result of Nate Anderson’s piece, “Deep packet inspection meets ‘Net neutrality, CALEA.” Anderson’s article is typically recognized as the popular news article that put DPI on the scene, and the American public’s interest in this technology was reinforced by Comcast’s use of TCP RST packets, which was made possible using Sandvine equipment. These packets (which appear to have been first discussed in 1981) were used by Comcast to convince P2P clients that the other client(s) in the P2P session didn’t want to communicate with Comcast subscriber’s P2P application, which led to the termination of the data transmission. Things continued to heat up in the US, as the behavioural advertising company NebuAd began partnering with ISPs to deliver targeted ads to ISPs’ customers using DPI equipment. The Free Press hired Robert Topolski to perform a technical analysis of what NebuAd was doing, and found that NebuAd was (in effect) performing a man-in-the-middle attack to alter packets as they coursed through ISP network hubs. This report, prepared for Congressional hearings into the surveillance of Americans’ data transfers, was key to driving American ISPs away from NebuAd in the face of political and customer revolt over targeted advertising practices. NebuAd has since shut its doors. In the US there is now talk of shifting towards agnostic throttling, rather than throttling that targets particular applications. Discrimination is equally applied now, instead of honing in on specific groups.

In Canada, there haven’t been (many) accusations of ISPs using DPI for advertising purposes, but throttling has been at the center of our discussions of how Canadian ISPs use DPI to delay P2P applications’ data transfers. Continue reading