• by Wendy Davis , Staff Writer @wendyndavis, June 18, 2014

Here's the good news: Broadband providers are doing a better job of making sure the speeds they deliver are around the same as what they advertised. What's more, average speeds have increased to 21.2 Mbps, compared to 15.6 Mbps one year ago.

That's according to the Federal Communications Commission's fourth annual report, released today, addressing how well broadband providers are fulfilling their marketing promises.

But here's the bad news: DSL providers -- not fast to begin with -- still deliver speeds slower than advertised.

FCC Chairman Tom Wheeler said in a statement that he has asked “underperforming companies” to explain why their service remains so poor. “I’m concerned that some providers are failing to deliver consistent speeds to consumers that are commensurate to their advertised speeds,” he stated.

For its report, the FCC examined performance of 14 Internet service providers last September, during the busiest hours -- weeknights from 7 P.M. to 11 P.M.

Some providers, including Cablevision and Verizon FiOS, offered faster service -- at least much of the time -- than promised. Others, however, fell short. Many DSL subscribers of Verizon,  Frontier, Windstream, and CenturyLink receive slower speeds than the companies promised, according to the report.

Verizon DSL subscribers’ average download speed was just 83% of the advertised speed, down from 88% last year. The download speeds of Frontier DSL users and Windstream DSL subscribers was 86% of the advertised speed, while CenturyLink offered users actual download speeds of 89% of the promised speed.

This report comes amid concern that network congestion is making it difficult for some broadband subscribers to stream video on Netflix. The FCC says its study showed “network congestion at certain interconnection points,” but that it excluded that data from the main report. The FCC says it intends to release that information separately.

Meanwhile, Netflix recently agreed to pay interconnection fees to Comcast and Verizon, in order to make sure subscribers are able to watch streaming video. The FCC said last week that it is investigating those deals.