Sling TV CEO Roger Lynch accused Comcast of setting its data caps just low enough to prevent customers from replacing cable TV with online video streaming.

In an interview with CordCutting.com today, Lynch said:

I think one of the areas we’re quite focused on is what’s happening in Washington, DC around net neutrality. We see concerning things happening if you look at cable companies like Comcast now instituting data caps that just happen to be at a level at or below what someone would use if they’re watching TV on the Internet—and at the same time launching their own streaming service that they say doesn’t count against the data cap. It’s something we’ve been warning Washington about for years, and it’s a risk to OTT [over-the-top Internet services] in general. We’re net neutrality proponents, and want to make sure that rules are implemented so that it really is a level playing field for new players like us.

Comcast is testing 300GB-per-month data caps in a variety of cities before a potential nationwide rollout. Customers are charged $10 for each additional 50GB, and in all but a few of the cities with data caps, they can pay an extra $30 or $35 per month for unlimited data.

Sling TV reportedly streams at speeds of 1.8Mbps to 4.5Mbps. At 4.5Mbps, it would take 148.15 hours to use 300GB. In a 31-day month, that's 4.8 hours of online TV streaming per day. That might sound like a lot, but Nielsen last year found that the average American adult spent four hours and 32 minutes watching live TV per day and another 30 minutes watching time-shifted TV each day.

Considering that families have multiple people watching different shows, these numbers indicate that it would be difficult for many American households to replace cable TV with Internet streaming if they face 300GB data caps. Even if they avoided all other types of Internet use, they could still end up paying overage fees to Comcast.

Sling TV, operated by Dish Network, launched earlier this year. The service offers live TV over the Internet starting at $20 a month. Netflix, still the king of online video in the US, streams at an average of 3.69Mbps to Comcast customers in the US, but can go up to 25Mbps with "Ultra HD" quality."

Dish is primarily a satellite TV provider but does offer satellite Internet. Dish's data caps are even more restrictive than Comcast's, but the company says its Internet service is only suitable for areas that have no other options. Data caps are pretty standard with satellite Internet, while the technically superior cable services generally have much higher limits or no caps at all.

Comcast’s own streaming video and net neutrality

Comcast, as Lynch said, is offering its own streaming service. Comcast's service provides in-home streaming of live TV to computers, tablets, and phones without a set-top box. To consumers watching on devices at home, the service would appear to be similar to offerings from Netflix or Sling TV, but Comcast's doesn't count against customers' data caps.

Lynch called this a net neutrality concern, and Sling could file a complaint against Comcast, but there's a good chance the Federal Communications Commission wouldn't side against the cable company. We've asked Sling if it plans a complaint but haven't heard back yet.

(UPDATE: Sling owner Dish replied to Ars but did not say whether it plans to file a net neutrality complaint. Instead, Dish pointed out that it filed a petition to deny Comcast's proposed acquisition of Time Warner Cable last year. The acquisition was blocked by regulators.)

Comcast's agreement to buy NBCUniversal requires it to treat its own traffic the same as competitors with regard to data caps. But Comcast notes that its streaming product "is an IP cable service delivered over our managed network to the home," rather than a service delivered over the Internet.

The FCC's net neutrality rules also don't specifically prevent ISPs from exempting their own streaming video from data caps. The FCC reserves the right to judge whether individual practices "unreasonably interfere" with the ability of consumers to reach content or the ability of content providers to reach consumers. That's why Sling could file a net neutrality complaint, but Comcast appears to think that it's on solid legal ground. ISPs are also trying to get those net neutrality rules overturned in court.

When contacted by Ars today, Comcast referred to a previous statement from the company that said, "Our data plan trials are based on a principle of fairness: those who consume more data pay more and those who use less pay less."

A Comcast spokesperson also pointed out that the company's data plans remain in trial mode and "we will continue to evaluate our policies. We want our customers to have a great online experience, and we want consumers to choose us because we offer the best Internet service in the marketplace.​"

So far, Sling TV's customers are mainly those who don't have traditional pay-TV service. "Only a very, very small percentage are people who have paid TV and then sign up for Sling TV," Lynch told CordCutting.com. "So we get people that have already cut the cord or people who have never had the cord."

Sling TV has had a few outages, and Lynch was asked to address complaints about streaming quality. Sling TV is working with its content delivery networks to improve performance, especially during peak viewing times, but Lynch said the technical hurdles remain formidable. "Streaming live TV over the Internet at the scale that we’re doing it is relatively new, and it’s a completely different animal than streaming on-demand content, because you have such little margin for error," he said.