Dynamics of random early detection

In this paper we evaluate the effectiveness of Random Early Detection (RED) over traffic types categorized as non-adaptive, fragile and robust, according to their responses to congestion. We point out that RED allows unfair bandwidth sharing when a mixture of the three traffic types shares a link. This unfairness is caused by the fact that at any given time RED imposes the same loss rate on all flows, regardless of their bandwidths.We propose Fair Random Early Drop (FRED), a modified version of RED. FRED uses per-active-flow accounting to impose on each flow a loss rate that depends on the flow's buffer use.We show that FRED provides better protection than RED for adaptive (fragile and robust) flows. In addition, FRED is able to isolate non-adaptive greedy traffic more effectively. Finally, we present a "two-packet-buffer" gateway mechanism to support a large number of flows without incurring additional queueing delays inside the network. These improvements are demonstrated by simulations of TCP and UDP traffic.FRED does not make any assumptions about queueing architecture; it will work with a FIFO gateway. FRED's per-active-flow accounting uses memory in proportion to the total number of buffers used: a FRED gateway maintains state only for flows for which it has packets buffered, not for all flows that traverse the gateway.

[1]  Sally Floyd,et al.  TCP and explicit congestion notification , 1994, CCRV.

[2]  Van Jacobson,et al.  Traffic phase effects in packet-switched gateways , 1991, CCRV.

[3]  QUTdN QeO,et al.  Random Early Detection Gateways for Congestion Avoidance , 1993 .

[4]  Robert Tappan Morris,et al.  TCP behavior with many flows , 1997, Proceedings 1997 International Conference on Network Protocols.

[5]  Larry L. Peterson,et al.  TCP Vegas: new techniques for congestion detection and avoidance , 1994 .

[6]  K. K. Ramakrishnan,et al.  Gateway Congestion Control Survey , 1991, RFC.

[7]  Janey C. Hoe.  Improving the start-up behavior of a congestion control scheme for TCP , 1996, SIGCOMM '96.

[8]  Sally Floyd,et al.  Connections with multiple congested gateways in packet-switched networks part 1: one-way traffic , 1991, CCRV.

[9]  Cheng Song,et al.  High performance TCP in ANSNET , 1994, CCRV.

[10]  H. T. Kung,et al.  TCP fast recovery strategies: analysis and improvements , 1998, Proceedings. IEEE INFOCOM '98, the Conference on Computer Communications. Seventeenth Annual Joint Conference of the IEEE Computer and Communications Societies. Gateway to the 21st Century (Cat. No.98.

[11]  George C. Polyzos,et al.  A Parameterizable Methodology for Internet Traffic Flow Profiling , 1995, IEEE J. Sel. Areas Commun..

[12]  H. T. Kung,et al.  Credit-based flow control for ATM networks: credit update protocol, adaptive credit allocation and statistical multiplexing , 1994, SIGCOMM '94.

[13]  K. K. Ramakrishnan,et al.  A binary feedback scheme for congestion avoidance in computer networks with a connectionless network layer , 1995, CCRV.

[14]  Van Jacobson,et al.  Congestion avoidance and control , 1988, SIGCOMM '88.

[15]  Sally Floyd,et al.  Simulation-based comparisons of Tahoe, Reno and SACK TCP , 1996, CCRV.

[16]  Charles A. Eldridge,et al.  Rate controls in standard transport layer protocols , 1992, CCRV.

[17]  Allison Mankin,et al.  Random drop congestion control , 1990, SIGCOMM '90.

[18]  John Nagle,et al.  On Packet Switches with Infinite Storage , 1985, IEEE Trans. Commun..

[19]  Lixia Zhang,et al.  A new architecture for packet switching network protocols , 1989 .

[20]  Jonathan S. Turner.  Maintaining high throughput during overload in ATM switches , 1996, Proceedings of IEEE INFOCOM '96. Conference on Computer Communications.

[21]  E. L. Hahne,et al.  Round robin scheduling for fair flow control in data communication networks , 1986, ICC.

[22]  Eman Salaheddin Hashem,et al.  Analysis of Random Drop for Gateway Congestion Control , 1989 .