A Better-Than-Best-Effort Service for Continuous Media UDP Flows*
Mark Parris, Kevin Jeffay, F. Donelson, Smith Jan Borgersen · 1998
The Internet community is very interested in addressing congestion with active queue management mechanisms like Random Early Detection (RED). Recent proposals extend these mechanisms to actively penalize “misbehaving” flows. These methods favor TCP and TCP-like flows strongly over other flows like UDP. In this paper we propose extensions to active queue management disciplines which continue to address congestion and reward TCPfriendly flows while minimizing impact on continuous media flows using other protocols. Our mechanism, Drop Preference Management (DPM), recognizes tagged flows and manages their latency while constraining the bandwidth they consume. We present empirical results of experiments comparing our mechanism to plain RED. 1. Overview As the Internet continues to evolve, increasing attention is being given to recognizing and addressing congestion within the network. Particularly, there is increasing focus on recognizing “well-behaved ” flows, those that respond to congestion by reducing the load they place on the network. Both Braden et al., and Floyd et al., recognize TCP flows with correct congestion avoidance implementations as well behaved [2, 6, 7, 1]. They argue that these flows, as “good network citizens, ” should be protected and isolated from the effects of “misbehaving ” flows. Misbehaving flows include incorrect implementations of TCP, unresponsive but lightweight UDP connections, and high bandwidth flows that aggressively retransmit when drops occur. A recent internet draft considers the problem of con-