On Tue, May 03, 2005 at 05:41:13PM +0200, Brian E Carpenter wrote: > The point is that (at the ISPs' request) the diffserv model allows > each ISP along the path to apply a different policy - so a packet > marked for EF treatment inside one ISP might be marked for AF > treatment inside another ISP. (You can argue that would be stupid, but > that's what the diffserv WG heard from the ISPs.) So different SPs will > interpret the same label differently.
How weird :) In the academic community, a lot of effort has been put in to agree some common DSCP semantics; this has been particulary useful for LBE, where end-to-end immutability of the DSCP is highly desirable (DSCP=8). If an ISP wants to apply local marking then it can, but one would hope the value would be restored on exit from the ISP's scope. I'm not aware of any research network that changes the value. You can test this with the traceroute -t option to set a DSCP value, and it'll report any change along the path. I tried this to a US commercial server, and no DSCP change was reported. WOuld be interesting to see who is seeing this happen in practice. -- Tim/::1 -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
