T-Mobile (NYSE:TMUS) CEO John Legere once again took a swipe at the competition, saying both Verizon (NYSE: VZ) and AT&T (NYSE: T) deliver lower-resolution video from Netflix than T-Mobile's Binge On provides. But the nation's two largest carriers say he's wrong.

"Did you know that when you watch Netflix on T-Mobile you get it at 480p?" Legere asked during a video T-Mobile posted yesterday announcing the addition of YouTube and other content partners to Binge On. "And the duopoly is actually delivering your Netflix content at 360p. I'll bet you didn't know that. Go check; it's true."

T-Mobile has come under fire for degrading and throttling video content for users of Binge On, which enables users to watch content without having an impact on their monthly data allotments. (The operator maintains that it "optimizes" video to ease traffic on the network while still delivering quality content.)

Even YouTube has taken issue with Binge On, noting in December that video is downgraded regardless of whether the provider is part of the program. And while the service has proven compelling to customers, it has also drawn flak from critics who oppose it on the grounds that it runs afoul of net neutrality principles.

Legere implied both Verizon and AT&T also downgrade the quality of video from Netflix, which has been a Binge On partner since the service's launch. But both operators flatly denied the allegation.

"Playback over LTE varies on network speeds, and we don't set a speed," Verizon's Chuck Hamby said, adding that factors such as weather and coverage can affect video resolution. "It's just a dopey claim and has no basis in fact at all."

AT&T echoed Hamby's thoughts. "Once again, T-Mobile is not giving you the complete facts," the operator said via email. "We do not reduce the resolution of any video on our network -- in fact, our customers on 4G LTE can get much higher resolution than T-Mobile's optimized 480p limit."

Mobile video must address many more variables and challenges than traditional, fixed-line video for larger screens, of course. It is transmitted over a range of networks including 3G and 4G, and viewed on a broad array of handsets and tablets, some of which are several years old. It's no surprise, then, that carriers continue to debate which network delivers the highest-quality content at the highest speeds.

For more:

- see this T-Mobile video

Related articles:

T-Mobile: Customers have watched 34 petabytes of video for no additional fee since Binge On launch

T-Mobile adds YouTube, adult content and more to Binge On

T-Mobile's Legere slams 'jerks' who question Binge On policies