The Federal Communications Commission (FCC) published a report that promised to shake up the broadband world.

To some extent, the report, “Measuring Broadband America,” provided results that weren’t very surprising but still good to see on paper. For example, the survey investigated broadband service by technology and found fiber optics provided the best results for both bandwidth and latency. Cable and digital subscriber line (DSL) followed, respectively.

Also, according to the report, “On average, during peak periods, DSL-based services delivered download speeds that were 82 percent of advertised speeds, cable-based services delivered 93 percent of advertised speeds, and fiber-to-the-home services delivered 114 percent of advertised speeds.”

In the latter case, Verizon’s FiOS service stood out in all areas, offering the best performance and even beating its advertised bandwidth by 14 percent. It also was completely unaffected by peak periods, while every other Internet service provider (ISP) showed a decline in performance.

The analysis by ISP is where the report stirred up controversy, revealing the weakness of most ISPs involved: the peak service period. Most notably, ISP Cablevision slumped to an astoundingly low 55 percent of its advertised bandwidth during peak periods and showed the greatest fluctuation out of the 13 ISPs in the study.

A Cablevision representative disputed the findings in an emailed statement to various media, stating, “Cablevision delivers some of the fastest Internet connections in the country, on our basic tier, two higher levels of service and our Wi-Fi network and this report simply does not reflect the experience of our nearly 3 million broadband customers. Our high-speed Internet product leads the nation in consumer adoption and has consistently won top ratings in much broader and more extensive consumer surveys conducted by J.D. Power Associates, PC magazine and others.”

Cablevision wasn’t the only ISP that scored poorly on the test. More than half of the ISPs involved in the study actually provided less than 100 percent of the bandwidth they advertised, and all but Verizon’s FiOS and Comcast dipped below their advertised bandwidth rates during peak hours.

The FCC stated the purpose of the report was not to defame but to inform. According to the report, “To make informed choices about purchasing and using broadband, consumers need to have access to basic information about broadband performance.” As a first-of-its-kind look at U.S. broadband, the report offers a new tool for choosing broadband service, and that’s good news for consumers. It isn’t such good news for some ISP marketing departments.