Gorry -
Authors, WG,
This note closes the IETF DCCP WGLC on CCID 4. During the LC,
comments were received from Arjuna (below) and to this I would also
like to add the following two comments. Please could the authors now
issue a revised ID to address these issues?
Thanks, I made the changes suggested by Arjuna.
Best wishes,
Gorry Fairhurst
DCCP Chair
---
Comments from WG Chair:
1) During the WG in San Francisco, the WG talked about whether the
dependency of this document on previous documents needs to be
clarified. Having re-examined the text, I can see there is scope
for a little more clarity in section 1.
RFC 4342 states:
3.1. Relationship with TFRC
The congestion control mechanisms described here follow the TFRC
mechanism standardized by the IETF [RFC3448]. Conforming CCID 3
implementations MAY track updates to the TCP throughput equation
directly, as updates are standardized in the IETF, rather than wait
for revisions of this document. However, conforming implementations
SHOULD wait for explicit updates to CCID 3 before implementing other
changes to TFRC congestion control.
CCID-4 in section 1 now writes:
"CCID 4 differs from CCID 3 in that CCID 4 uses TFRC-SP,
the Small-Packet variant of TFRC [RFC4828], while CCID 3 [RFC4342]
uses standard TFRC [RFC3448]. (At the time of writing of this
document, [RFC3448] has been obsoleted by [RFC5348]. However,
[RFC4342] predates [RFC5348], and refers instead to [RFC3448].) This
document assumes that the reader is familiar with [RFC4342], instead
of repeating from that document unnecessarily."
- Would the authors please consider reworking this a little?
- CCID 4 is derived from RFC 4342 and hence inherits from RFC 3448.
But, it is my understanding that TFRC-SP also includes an update
from TFRC.bis, now published as RFC 5348. We need to be clear
whether CCID 4 assumes the updates in RFC5348 should also be applied
when implementing CCID 4.
The draft now says this:
"This document specifies an experimental profile for Congestion
Control Identifier 4, TCP-Friendly Rate Control for Small Packets
(TFRC-SP), in the Datagram Congestion Control Protocol (DCCP)
[RFC4340]. CCID 4 is a modified version of Congestion Control
Identifier 3, CCID 3, which has been specified in [RFC4342]. This
document assumes that the reader is familiar with CCID 3 instead of
repeating from that document unnecessarily."
"CCID 3 uses TCP Friendly Rate Control (TFRC), whith is now
specified
in RFC 5348 [RFC5348]. CCID 4 differs from CCID 3 in that CCID 4
uses TFRC-SP [RFC4828], an experimental, small-packet variant of
TFRC. The original specification of TFRC, RFC 3448 [RFC3448], has
been obsoleted by RFC 5348. The CCID 3 and TFRC-SP documents both
predate RFC 5348 and refer instead to RFC 3448 for the specification
of TFRC. However, this document assumes that RFC 5348 will be used
instead of RFC 3448 for the specification of TFRC."
2) I often use the formulation "CCID-3" and "CCID-4" when I write
about DCCP, but so far in standards documents we have not hyphenated
the CCID labels. Could the authors please update this document to
consistently use the non-hyphenated style?
Done.
Many thanks for the feedback.
I will submit the revised draft in the next few days.
- Sally
http://www.icir.org/floyd/
