Cogent said they prioritized data based on user type “putting its retail customers in one group and wholesale in another.” Cogent said “retail customers were favored because they tend to use applications, such as VoIP, that are most sensitive to congestion” and that they “implemented a QoS structure that impacts interconnections during the time they are congested.” Cogent classified M-Lab performance tests into the highest priority class. As they did so, this change instantly and dramatically improved the M-Lab test results. [Described by Susan Crawford as “the Cliff and the Slope” – it appears the cliff was Cogent taking on Netflix and the slope was the introduction of a fast lane on the Cogent network] The fact that the high priority traffic class so quickly improved M-Lab’s test performance demonstrates conclusively that there must have been significant congestion present in Cogent’s network. Cogent now admits to impacting third-party content and says they did it as a “last resort effort to help manage the congestion and its impact to our customers”.