Subject: erratum for RFC 4342

From: Eddie Kohler <[email-masked]>
Date: Sun, 17 Dec 2006 18:39:16 -0800

Hello RFC editor,

Attached is an erratum for RFC 4342.  Thanks very much for including 
this on the erratum page.

Eddie Kohler & Sally Floyd

RFC 4342, "Profile for Datagram Congestion Control Protocol (DCCP)
Congestion Control ID 3: TCP-Friendly Rate Control (TFRC)"

Reported By: Sally Floyd and Eddie Kohler, from Gerrit Renker
Date: 17 December 2006

Section 5, 7th paragraph:
Explanation: Clarification of round-trip time measurement

It states:
    The sender's measurement of the round-trip time uses the Elapsed Time
    and/or Timestamp Echo option contained in feedback packets, as
    described in Section 8.2. The Elapsed Time option is required, while
    the Timestamp Echo option is not.  The sender maintains an average
    round-trip time heavily weighted on the most recent measurements.

It should say:
    The sender uses DCCP's mechanisms to measure round-trip times.  This
    includes Elapsed Time and/or Timestamp Echo options, and as described
    in Section 8.2, feedback packets MUST carry Elapsed Time options.
    Senders MAY additionally make use of other available RTT
    measurements, including those from the initial Request-Response
    packet exchange.  This differs from [RFC3448], which constrains RTT
    measurement to feedback packets only.  For CCID 3 calculations, the
    sender uses an average round-trip time heavily weighted on the most
    recent measurements.