The idea here is pretty clear: these five ISPs want to be paid extra for doing the job they are already being paid for. Extra ports are required to handle the current level of traffic and these companies are assuming that when the pain becomes great enough — that’s our pain, by the way — Level3 or some Level3 customer like Netflix will pay the extra money to make the problem go away.
The major ISPs (basically any one of Comcast, Time Warner Cable, CenturyLink, Charter Communications, AT&T U-verse, Cox Communications, and Verizon FiOS) want to essentially freeze the current, busted-ass, infrastructure, and get end-users and major traffic users like Netflix to pay for the newer, better, infrastructure, then charge us all extra after we’ve paid for it. Net Neutrality has to die for them to achieve this, so they’re making their big push to kill it.