Last month we explored how Comcast and Sandvine's network management technology continues to evolve. Unlike Comcast's last system, which throttled upstream traffic for all users regardless of consumption, this new system identifies customers and throttles back consumption only if they're on a congested node -- and they're a particular reason why. Even then, we haven't seen complaints from users in our Comcast forum, which is a very good sign.

Deep packet inspection (DPI) has many legitimate uses on an ISP network, but has gained notoriety in recent years for its use in delivering behavioral ads, injecting ISP javascript banners into websites, and filtering or throttling P2P traffic. Like most technology DPI isn't inherently bad, but the way it can be used and mis-used by carriers or governments certainly may be.

As the debate over DPI and network neutrality reheats here and in Canada, companies like Sandvine have entered damage control mode. Sandvine, in recent filings with Canadian regulators, offered some stats suggesting that discriminatory traffic shaping is the new black, and everybody's doing it. In a filing, Sandvine notes that DPI usage is literally everywhere, and therefore lawmakers and the public have nothing to worry about:After a slew of recent missteps and several bouts of dishonesty, Comcast has done an excellent job with their new combination of non-annoying network management and a high, transparent and reasonable 250GB cap (so far, without obnoxious overages); but the change didn't come easy. It wouldn't have happened without educated consumers holding the company accountable, and at least the threat of government intervention. It took time too; users complained about Comcast's "invisicap" for most of the decade.

To their credit, Comcast's also being aggressive about network upgrades, and will have 65% of their customers upgraded with DOCSIS 3.0 technology by the end of this year, and all customers upgraded by 2010. Comcast's also exploring 120Mbps upstream DOCSIS 3.0 trials this year, as upstream channel bonding becomes standard.

Problems with Sandvine and DPI come into play when ISPs (Bell Canada comes to mind) embrace network throttling as a way to skimp on infrastructure upgrades -- in order to placate myopic and impatient investors. Many ISPs also use Sandvine gear to throttle by application, and many others are intent on offering consumers increasingly lower quality bandwidth at increasingly higher prices. It's going to be a constant fight to keep carriers honest about network management as the tech evolves, and that job lies primarily with consumers.