As Jack has completed his updates to RFC 2553, I've put it back on the IESG for consideration for publication. That prompted the following comment from Bill Fenner.
Thoughts on how to proceed? ================ Thomas, Here's an issue that I just discovered today. I can't tell whether it's a 2553bis issue or a 2292bis issue (or both). 2553bis says: The sin6_flowinfo field is a 32-bit field that contains two pieces of information: the traffic class and the flow label. The contents and interpretation of this member is specified in [1]. [1] is RFC 2460, and doesn't really say anything about sin6_flowinfo per se, but does have the picture of the first 32 bits of the IPv6 packet, and knowing history I know it means that the bottom 28 bits of the sin6_flowinfo field goes after the version. 2292bis says to use the IPV6_TCLASS socket option or ancillary data and doesn't mention sin6_flowinfo. To specify the outgoing traffic class value, just specify the control information as ancillary data for sendmsg() or using setsockopt(). I think having two different ways to specify the traffic class is confusing, especially since 2292bis doesn't refer to the 2553bis way, nor does it say which one is actually used if both are specified. Another problem is that 2460 doesn't say what to put in the sin6_flowinfo (although you can kind of guess), so 2553bis's assertion that 'The contents and interpretation of this member is specified in [1].' is not really true. A possible solution to both of these problems is to remove the traffic class from the sin6_flowinfo, and define the sin6_flowinfo to just contain the 20 bit Flow Label. If the solution is to instead expand 2292bis to talk about the interaction with sin6_flowinfo, then 2553bis should define the actual contents of sin6_flowinfo, not just vaguely refer to 2460. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | Traffic Class | Flow Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ would probably be fine. Bill -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
