Administratively assigning different priorities to different types of traffic is appealing, but impractical as a long-run solution to congestion costs due to the usual inefficiencies of rationing. From the network's perspective, bits are bits and there is no certain way to distinguish between different types of uses. The most obvious approach for economists is to charge some sort of congestion price. However, to date, there has been almost no serious consideration of congestion pricing for backbone services, and even tentative proposals for usage pricing have been met with strong opposition. We will discuss pricing below but first we examine some non-price mechanisms that have been proposed.
Many proposals rely on voluntary efforts to control congestion.
Numerous participants in congestion discussions suggest that peer pressure and user ethics will be sufficient to control congestion costs. And of course, peer pressure may be quite ineffective against malicious users who want to intentionally cause network congestion. This proposal would require users to indicate the priority they want each of their sessions to receive, and for routers to be programmed to maintain multiple queues for each priority class. Obviously, the success of this scheme would depend on users' willingness to assign lower priorities to some of their traffic. In any case, as long as it is possible for just one or a few abusive users to create crippling congestion, voluntary priority schemes that are not robust to forgetfulness, ignorance, or malice may be largely ineffective.