The CRTC received 75 complaints of traffic throttling last year against Internet providers large and small, some with multiple complaints.
"There are providers who have had multiple complaints, but it does go the whole gamut of types of service providers," the CRTC's Lynne Fancy said Thursday.
From an Internet user's perspective, the traffic throttling can cause slower download speeds or jerky video streaming.
"It's generally individuals who are complaining," said Fancy, director general of competition, costing and regulatory implementation at the CRTC.
The Canadian Radio-television and Telecommunications Commission, which oversees the providers, didn't provide a list of companies that faced complaints in 2012.
Fancy said 11 of the 75 complaints were still being investigated.
Non-profit advocacy organization OpenMedia.ca said the onus remains on the consumer to report any traffic throttling to the CRTC.
Spokeswoman Lindsey Pinto said that process can be lengthy and complicated.
"The CRTC doesn't really have strong compliance or enforcement on this so it's kind of up to the consumer to report to the CRTC when they see discriminatory practices taking place," Pinto said.
"We're going to continue to see problems until some kind of enforcement regime is put into place."
The CRTC doesn't have the power to fine an Internet service provider for traffic throttling, but Fancy said "nothing stops us from continuing to investigate from our perspective if we would suspect that there was a trend or something's happening."
The CRTC doesn't have comparative statistics for 2011 because it changed the guidelines for complaints that year. But between Oct. 1 2009, and Sept. 30, 2011 there were 67 complaints, Fancy said.
Pinto said traffic throttling is largely done by the big telecom companies.
In one well-known example, the Canadian Gamers Organization complained that Rogers Communications (TSX:RCI.B) had been slowing traffic related to online games, which the company eventually admitted.
But last June, the CRTC said it was confident that Rogers had ceased slowing Internet gaming activities on its network.
"A number of providers have changed their practices to the benefit of consumers," Fancy said.
"There are many reasons, for example, why your Internet service might slow down," she said. "Sometimes after investigation there are other reasons why the Internet may have been slow."
The CRTC's guidelines say that if an Internet service provider fails to respond to a complaint about traffic management or doesn't comply with CRTC guidelines on compliance, it can meet with the provider to discuss a complaint in more detail.
The commission can also request an on-site inspection or independent third-party audit, or call the Internet provider to a public hearing.
If the CRTC finds that an Internet service provider is not in compliance with its, the commission's guidelines say it will publish the company’s name and the nature of the complaint.
She also noted there consumers and organizations that closely follow Internet traffic management and "we would probably tend to hear quite quickly" about any problems.