Comcast has agreed to let its customers stream HBO and Showtime on Roku devices.

It wasn't clear why Comcast blocked the HBO and Showtime apps on Roku boxes while allowing them on other hardware, such as the Apple TV. Roku complained about the situation to the Federal Communications Commission and was recently able to wring an agreement out of Comcast.

Ater several months of negotiations, "Roku is pleased to inform the Commission that effective November 25, 2014, Roku and Comcast entered into an agreement pursuant to which Comcast has, among other things, agreed to authenticate the HBO GO and Showtime Anytime apps on Roku video streaming devices for Comcast's subscribers whose subscriptions entitle them to access the content and services made available through such apps," Roku wrote in an FCC filing yesterday. The filing was submitted for the FCC's proceeding on Comcast's proposed purchase of Time Warner Cable and its proceeding on net neutrality rules.

The Roku/Comcast problem illustrated how tying cable TV subscriptions to online streaming services can harm consumers. In a Roku filing in the FCC's net neutrality proceeding, the company argued that authentication systems run by Internet service providers can be used to pick and choose which hardware platforms customers may use to access streaming services. ISPs could demand payment from operators of third-party streaming platforms in exchange for not blocking content, the filing suggests.

"Rather than prioritizing platform support by customer interest or software compatibility, MVPDs [multichannel video programming distributors] can use their power of authentication to favor one streaming platform over another. A large and powerful MVPD may use this leverage in negotiations with content providers or operators of streaming platforms, ultimately favoring parties that can either afford to pay for the privilege of authentication, or have other business leverage that can be used as a counterweight to discriminatory authentication," Roku wrote. "Additionally, MVPDs with affiliated ISPs can abuse their power over authentication by choosing to authenticate only their own or affiliated offerings."

We asked Roku if it had to pay Comcast to complete this latest deal. The company responded, "Roku doesn't disclose details of our partner agreements." Roku posted a blog today saying that Comcast customers can activate HBO GO and Showtime on Roku immediately.

Roku also described Comcast's previous refusal to authenticate HBO Go and Showtime Anytime in an August 25 filing on the Comcast/Time Warner Cable merger.

"While Time-Warner has authenticated the HBO Go app and the Showtime Anytime app on Roku’s platform, Comcast has not authenticated either app," Roku wrote. "Moreover, Time-Warner executives have announced that they 'will be knocking down some of the current obstacles... so that customers can have nothing but a Roku device or an Xbox and get their video experience.' Comcast has gone the other way, prioritizing its Xfinity platform, which competes with third party streaming platforms by providing streaming video content on demand."

We've asked Comcast why it blocked HBO Go and Showtime on Roku, and for more information on the new agreement with Roku, but haven't heard back yet.

This isn't the end of streaming troubles for Comcast subscribers. In a story titled, "HBO Go Comes to Amazon Fire TV (Unless You Have Comcast)," DSLReports wrote today, "HBO Go this week announced that the streaming service has been made available to Amazon Fire TV owners today, with Fire Stick customers having access to the app sometime in the Spring. Of course if you head to activate your device, you'll find that Comcast and Charter aren't supported. Why the companies are blocking a relatively uncomplicated app and authentication service isn't clear. Amazon says that negotiations are ongoing."