On (2005-05-25 11:49 -0400), Valdis.Kletnieks@vt.edu wrote:
Out of curiosity, what did you hope to accomplish by zeroing that field?
IMHO only reason not to zero TOS byte on AS ingress border is that you explicitly agreed with your neighbour how it is used (what traffic it can contain, what is the absolute limit they will send that traffic in, etc.) I personally don't want to see DoS traffic taking eg. VoIP priority. I've been also thinking about possibility to differentiate in MPLS EX/TOS AS internal and AS external traffic and under congestion start to drop AS external traffic first.
(If you're planning to zero it on ingress to your network, use it for your own nefairious traffic-engineering purposes, and then re-zero on egress, *and* your contracts with your customers say it's OK to do it, then it might be defensible. Maybe. ;)
-- ++ytti