On protective buffer policies

We study buffering policies which provide different loss priorities to packets/cells with no change in packet ordering (space priority disciplines). These policies are motivated by the possible presence, within the same connection, of packets with different loss probability requirements or guarantees. Examples of such applications are voice and video coders that generate information of unequal importance, and rate control mechanisms that mark excess traffic with a low priority rate violation tag. The main issue being investigated is the identification and the evaluation of buffering policies that can guarantee performance, i.e., loss probability, to high priority packets irrespective of the traffic intensity and arrival patterns of low priority packets, while preserving the original ordering among packets. Such policies are termed protective policies.