Margaret: I completely agree with you that unless we have a signalling/flow-establishment mechanism we cannot really define the flow-label usage in a meaninful way. Perhaps we should wait until new NSIS sginalling might come-up with some usage and mechanism for this bit-space.
- Muhammad Jaseemuddin Margaret Wasserman wrote: > >Hi All, > >I am wondering why we should specify the use of the flow label as >part of the base IPv6 specifications at all. Why do we need >these rules as part of IPv6? > >The flow label does not, by itself, provide any useful information >that a router can use to classify a flow and/or optimize packet >handling. In fact, without knowledge of a specific signalling >mechanism or flow-establishment mechanism, the router can't >use the flow label for anything at all. For example, a router >cannot use a flow label for QoS queuing or to optimize hop-by-hop >header processing, unless the router is aware of the signalling/ >flow-establishment mechanism in use, since it will not >know the flow lifetime. > >Any rules governing how the flow label is chosen, modified, >authenticated and/or interpreted will be specific to the >signalling/flow-establishment mechanism in use. And, all of >the nodes/routers that are utilizing one of these mechanisms >will be aware of the mechanism. > >So why not specify the semantics/use/etc. of the flow label as >part of the signalling/flow establishment protocols? > >The IPv6 specifications could merely include the current rule: > >"Hosts or routers that do not support the functions of the Flow Label >field are required to set the field to zero when originating a packet, >pass the field on unchanged when forwarding a packet, and ignore the >field when receiving a packet." [from RFC 2460]. > >This rule should properly protect the flow label, so that >signalling/flow-establishment mechanisms can use the flow >label, as needed by the specific mechanism. > >Margaret > > > > > > > > > > >-------------------------------------------------------------------- >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] >-------------------------------------------------------------------- > -------------------------------------------------------------------- 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] --------------------------------------------------------------------
