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ATM Forum Document Number: ATM Forum/94-0988 

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Title: Simulation Results: The EPRCA+ Scheme

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Abstract:

Simulation results comparing EPRCA and EPRCA+ are presented.  In
particular, EPRCA+ has fast transient performance, offers congestion
avoidance, has few parameters, and is parameter insensitive. 

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Source:

Raj Jain, Shiv Kalyanaraman and Ram Viswanathan\\
The Ohio State University\\
Department of CIS\\
Columbus, OH 43210\\
Phone: 614-292-3989, Fax: 614-292-2911, Email: Jain@ACM.Org

The presentation of this contribution at ATM Forum is sponsored by NIST.

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Date: October 25-26, 1994

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Distribution: ATM Forum Technical Working Group Members (Traffic Management)

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Notice: This contribution has been prepared to assist the ATM Forum.  It
is offered to the Forum as a basis for discussion and is not a binding
proposal on the part of any of the contributing organizations.  The
statements are subject to change in form and content after further
study.  Specifically, the contributors reserve the right to add to,
amend or modify the statements contained herein. 

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EPRCA+ is the simplified version of the OSU scheme [1] presented in the
September meeting. In particular, we have changed from dual rate
specification to a single rate. The RM cell contains only the current
cell rate. This is similar to EPRCA [2]. Secondly, we have removed the
Reduction-Factor field and replaced it with ``Explicit Rate.''

Since both EPRCA+ and EPRCA are derivatives of the MIT scheme [3], they
follow the same basic steps. The major difference is that EPRCA+ is
time-based in the sense that RM cells are sent $T$ microseconds apart
rather than after Nrm-th cell. This give a fast response time to EPRCA+.
The rate reaches the final steady state valule with $T$ microseconds in
case of EPRCA+ while it takes several milliseconds for EPRCA. Since most
of the networks operate in the transient state most of the time this is
an important consideration. 

EPRCA+ has most of advantages of the OSU scheme including being
parameter insensitive, uses measured overload, the oscillations are
bounded. 

[1] Raj Jain, Shiv Kalyanaraman, Ram Viswanathan, ``The OSU Scheme for
Congestion Avoidance Using Explicit Rate Indication,'' AF-TM 94-0883,
September 1993. 

[2] L. Roberts, et al, ``Enhanced Proportional Rate Control Algorithm,''
AF-TM 94-0735, September 1993. 

[3] Anna Charney, Dave Clark, Raj Jain, ``Congestion Control with
Explicit Rate Indication,'' AF-TM 94-0692, July 1994.