Words are funny things; while "quizzes" can be fun, the very similar "interrogations" usually aren't. And interrogation is exactly what the Canadian Radio-television and Telecommunications Commission (CRTC) has in mind for Bell Canada. Late last week, the regulator issued a detailed set of "interrogatories" (PDF) complete with chart that must be filled in by May 29. The goal is to find out exactly how Bell's deep packet inspection technology throttles traffic and the justifications for using it on all Bell traffic, even that sold at wholesale rates to smaller ISPs. Anyone interested in these matters stands to learn plenty of interesting information 10 days from now.

One of the claims that Bell Canada makes in its defense is that 5 percent of users generate 60 percent of its total traffic and that 60 percent of this total traffic is P2P that is negatively impacting 95 percent of all customers (did you follow that?). The CRTC wants to see the calculations, and it wants to Bell Canada to show its work. "Provide full rationale and evidence in support of Bell Canada's view that 95 percent of its customers were being negatively affected," says the first of the CRTC interrogatories.

The list of questions goes on:

Explain in detail how the values for total traffic and P2P traffic during the peak period were determined. The explanation should describe how measurements were carried out, indicating the period of time over which measurements were taken, what peak period was used, whether a single sample or an average of are multiple days (indicate number of days) was used

Describe all other approaches, if any, considered by Bell Canada as an alternative to shaping P2P traffic to address the network congestion it described, and explain why each approach was rejected. Include a discussion of the conditions under which Bell Canada would augment its network capacity to address congestion

Provide data on the growth of traffic on Bell Canada's network for supporting Internet access from 2004 to 2008, indicating the mix of P2P and non-P2P traffic over time. Further, describe to what extent Bell Canada has increased its network capacity to support the traffic growth

In paragraph 14 of its Answer, Bell Canada submitted that "the actual content of the packet is not examined, just the protocol headers encapsulating the content." Discuss whether the DPI technology deployed by Bell Canada has the capability to examine the content of the P2P traffic being shaped and to identify the sender and the intended recipient



Please fill this in and show your work

The gist of these questions is clear: Bell has to detail the methodology behind these traffic claims, claims that are often put forward by both ISPs and DPI providers, but which generally don't describe the way the information was gleaned. In addition, the CRTC is going to take on the thorny question of when and how ISPs should be allowed to throttle and whether they are doing it in place of making necessary network upgrades. And if that's not enough, the regulator wants detailed information on Internet traffic growth that ISPs are generally reluctant to provide in much detail (we took a look at the estimates last month).

Given all these meaty questions, it's no wonder that CRTC head Konrad von Finckenstein said recently that the Bell Canada complaint "will have wide-ranging consequences and will lead to a much wider debate. This will undoubtedly occupy much of our time this year." Michael Geist, who noted both the CRTC letter and Finckenstein's comment, calls the plan "an aggressive timeline." A decision should be made within 90 days of the final June 26 comment date, by which point the FCC might finally have produced a ruling of its own in its investigation of comcast.

The CRTC has already refused to stop Bell's throttling on an interim basis, but might well come to a different conclusion when the full process is complete. Given the thoroughness of the questions and the interesting data called for in the interrogatories, the CRTC at least seems willing to give the matter real attention. Between the Comcast case pending at the FCC and the Bell Canada case at the CRTC, 2008 could see a boom in seminal regulatory opinions on the use of DPI as a throttling technology.