RFC 4342 Errata:
Reported By: Sally Floyd; floyd@acm.org
Receive Rate Adjustment

Section 8.3 of RFC 4342 (DCCP CCID 3) specifies that the Receive
Rate option reports the receive rate since the last feedback packet
was sent.  In contrast, Section 6.2 of RFC 3448 (TFRC) specifies
that the feedback packet reports the receive rate over the last
round-trip time.  As a result, the receive rate specified by 
RFC 4342 differs from that of TFRC for a feedback packet after an
idle period; the receive rate report specified in RFC 4342 reports
the receive rate over the entire idle period.  The receive rate
reported by RFC 4342 also differs from that of TFRC for an early
feedback packet reporting a new loss event.  This errata updates
RFC 4342 to use the definition of the receive rate as specified in
RFC 3448.

RFC 4342, Section 6, the fourth paragraph says:

      2. A Receive Rate option, defined in Section 8.3, specifying the
         rate at which data was received since the last DCCP-Ack was
         sent.

It should say:

      2. A Receive Rate option, defined in Section 8.3, specifying the
         rate at which data was received over the last round-trip time.


RFC 4342, Section 8.3, the first paragraph says:

      Its four data bytes indicate the rate at which
      the receiver has received data since it last sent an
      acknowledgement, in bytes per second.  To calculate this receive
      rate, the receiver sets t to the larger of the estimated round-
      trip time and the time since the last Receive Rate option was
      sent.  

It should say:

      Its four data bytes indicate the rate at which
      the receiver has received data over the last round-trip time,
      in bytes per second.  To calculate the time interval t for
      calculating this receive rate, the receiver follows Section
      6.2 of [RFC3448].


The following paragraph specifies that if the interval covered by
a feedback packet doesn't include any data packets, then the sender
doesn't have to use the reported receive rate.

RFC 4342, Section 8.3, should have the following paragraph
added to the end of the section:

      Assume that the sender receives two feedback packets with
      Acknowledgement Numbers A1 and A2, respectively.  Further assume
      that the sender sent no data packets in between Sequence Numbers
      A1+1 and A2, inclusive.  (All those packets must have been pure
      acknowledgements, Sync and SyncAck packets, and so forth.)  Then
      the sender MAY, at its discretion, ignore the second feedback
      packet's Receive Rate option.  Note that when the sender decides
      to ignore such an option, it MUST NOT reset the nofeedback timer
      as it normally would; the nofeedback timer will expire as if the
      second feedback packet had not been received.