The FCC launched an investigation into Comcast’s network management practices earlier this year following accusations that the company is blocking access to certain file sharing applications on its network. Looking to gather additional information on the situation, the agency opened a public comment period on whether “degrading peer-to-peer traffic” violates FCC rules for reasonable network management.

Today is the deadline for that comment period and Comcast has responded with a filing with the FCC admitting it messes with certain P2P protocols, but only “in a minimally intrusive way, and only when necessary, based on purely objective criteria.”

Comcast explains that its P2P throttling is not based on the content of the files users are sharing or the identity of the users who are doing the sharing, and that its techniques: only affect the protocols that have a demonstrated history of generating excessive burdens on the network, only manage those protocols during periods of heavy network traffic, and only manage uploads (when the customer is not simultaneously downloading) with the goal of stopping unattended machines from using significant upload bandwidth.

The company maintains that this network management is “reasonable” and that it is fully consistent with the FCC’s 2005 Internet Policy Statement. Consumer groups and some Internet companies, however, argue that blocking or slowing users’ access to the web collides with the very principles of a fair and open Internet.