[rfc-dist] RFC 4828 on TCP Friendly Rate Control (TFRC): The Small-Packet (SP) Variant

rfc-editor@rfc-editor.org rfc-editor at rfc-editor.org
Mon Apr 16 11:32:17 PDT 2007

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        RFC 4828

        Title:      TCP Friendly Rate Control (TFRC): 
                    The Small-Packet (SP) Variant 
        Author:     S. Floyd, E. Kohler
        Status:     Experimental
        Date:       April 2007
        Mailbox:    floyd at icir.org, 
                    kohler at cs.ucla.edu
        Pages:      46
        Characters: 116808
        Updates/Obsoletes/SeeAlso:   None

        I-D Tag:    draft-ietf-dccp-tfrc-voip-07.txt

        URL:        http://www.rfc-editor.org/rfc/rfc4828.txt

This document proposes a mechanism for further experimentation, but
not for widespread deployment at this time in the global Internet.

TCP-Friendly Rate Control (TFRC) is a congestion control mechanism
for unicast flows operating in a best-effort Internet environment
(RFC 3448).  TFRC was intended for applications that use a fixed
packet size, and was designed to be reasonably fair when competing
for bandwidth with TCP connections using the same packet size.  This
document proposes TFRC-SP, a Small-Packet (SP) variant of TFRC, that
is designed for applications that send small packets.  The design
goal for TFRC-SP is to achieve the same bandwidth in bps (bits per
second) as a TCP flow using packets of up to 1500 bytes.  TFRC-SP
enforces a minimum interval of 10 ms between data packets to
prevent a single flow from sending small packets arbitrarily

Flows using TFRC-SP compete reasonably fairly with large-packet TCP
and TFRC flows in environments where large-packet flows and
small-packet flows experience similar packet drop rates.  However, in
environments where small-packet flows experience lower packet drop
rates than large-packet flows (e.g., with Drop-Tail queues in units
of bytes), TFRC-SP can receive considerably more than its share of
the bandwidth.  This memo defines an Experimental Protocol for the 
Internet community.

This document is a product of the Datagram Congestion Control Protocol
Working Group of the IETF.

EXPERIMENTAL: This memo defines an Experimental Protocol for the Internet 
community. It does not specify an Internet standard of any kind. 
Discussion and suggestions for improvement are requested.  Distribution 
of this memo is unlimited.

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