Hi,
It has recently come to our attention that the CCID 3 RFC
doesn't explicitly
say that ANY valid RTT measurement may be used to update the
CCID 3 RTT. This
wasn't the intent. We [Sally & Eddie] propose to send
in the following
erratum. Comments?
Eddie
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:
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's measurement of the round-trip time uses
DCCP's mechanisms
for round-trip time measurement. This includes Elapsed
Time and/or
Timestamp Echo options. As described in Section 8.2,
feedback packets
must carry an Elapsed Time option; Timestamp Echo is
optional.
The sender maintains an average round-trip time heavily
weighted on the
most recent measurements. Senders MAY use any available
round-trip time
measurements, including from the initial
Request-Response packet exchange,
to maintain this average. This differs from [RFC 3448],
which constrains
round-trip time measurements to feedback packets only.
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