[e2e] Using history in window control

[Ibrahim Matta]

Dear all,

We  would appreciate very  much your  feedback on  our recent  work on
TCP-friendly window-based  congestion control.  In this  paper, we are
exploring a  new design space between memory-less  window controls and
equation-based controls  which use  more history. Please  see abstract
below and technical report at

http://www.cs.bu.edu/techreports/2001-015-spectrum-tcp-friendly.ps.Z

This work  addresses issues  raised in the  upcoming Sigcomm  paper of
Bansal et al. regarding slowly-responsive protocols.

Also, our  upcoming ICNP paper  studies an instance of  this spectrum,
called  SIMD (Square-Increase/Multiplicative-Decrease).  The technical
report is at

http://www.cs.bu.edu/techreports/2001-006-simd.ps.Z


Best regards.

--
Ibrahim Matta       Dept of Comp Sci, 111 Cummington St, MCS-271
matta at cs.bu.edu     Assistant Prof, Boston Univ., Boston, MA 02215
Tel: (617)358-1062, Fax: (617)353-6457, URL: www.cs.bu.edu/fac/matta/

===========

Title:
 A Spectrum of TCP-friendly Window-based Congestion Control Algorithms

Author: Shudong Jin, Liang Guo, Ibrahim Matta, Azer Bestavros
        {jins, guol, matta, best}@cs.bu.edu

        Computer Science Department
        Boston University

Date: February 2, 2001
      Revised on April 27, 2001
      Posted on July 12, 2001


Abstract:

 The  increased  diversity of  Internet  application requirements  has
 spurred  recent  interests   in  transport  protocols  with  flexible
 transmission  controls. In  window-based congestion  control schemes,
 increase rules  determine how  to probe available  bandwidth, whereas
 decrease  rules  determine  how  to  back  off  when  losses  due  to
 congestion are detected.  The parameterization of these control rules
 is done so  as to ensure that the  resulting protocol is TCP-friendly
 in terms of the relationship between throughput and loss rate.

 In this  paper, we define  a new spectrum of  window-based congestion
 control algorithms  that are  TCP-friendly as well  as TCP-compatible
 under RED.  Contrary to previous memory-less controls, our algorithms
 utilize  history information  in  their control  rules. Our  proposed
 algorithms have two salient features:  (1) They enable a wider region
 of TCP-friendliness,  and thus more flexibility in  trading off among
 smoothness, aggressiveness, and responsiveness; and (2) they ensure a
 faster  convergence  to  fairness   under  a  wide  range  of  system
 conditions.  We  demonstrate analytically and  through extensive {\em
 ns} simulations  the steady-state and transient  behaviors of several
 instances of this new spectrum  of algorithms. In particular, SIMD is
 one   instance  in   which   the  congestion   window  is   increased
 super-linearly   with  time   since   the  detection   of  the   last
 loss. Compared  to recently  proposed TCP-friendly AIMD  and binomial
 algorithms, we  demonstrate the superiority of SIMD  in: (1) adapting
 to  sudden  increases   in  available  bandwidth,  while  maintaining
 competitive smoothness and responsiveness; and (2) rapidly converging
 to fairness and efficiency.

Keywords:
 Congestion Control, TCP-friendliness, Fairness, Convergence.