Dear All, agree with Weiguo, single bit flag in fixed position would be sufficient and HW-friendly.
Regards, Greg On Tue, Nov 11, 2014 at 3:51 PM, Haoweiguo <[email protected]> wrote: > Hi Larry, > > For marking purpose, i think one bit maybe OK, fixed fields in NVO3 header > is precious. I would like it is set in fixed field, rather than in option > field. Because chipset normally can't process optional field, it is hard to > realize in-band performance measurement if using optional field for > marking. For other real time congestion control function, maybe more bits > are needed. > > Thanks > > weiguo > ------------------------------ > *发件人:* Larry Kreeger (kreeger) [[email protected]] > *发送时间:* 2014年11月12日 4:33 > *收件人:* Haoweiguo; Greg Mirsky > > *抄送:* [email protected] > *主题:* Re: [nvo3] Comments on NVO3 data plane requirements for OAM > > Hi Weiguo, > > What do you envision this marking looking like? e.g. is it just a > single flag bit, or large field with a counter or sequence number, or some > kind of flow ID? If not a single flag, how large do you see the field > being? > > If it is more than a flag (and I assume it would be), and is not > mandatory for all implementations, then it seems to fall into the category > of optional extensions. > > Thanks, Larry > > From: Haoweiguo <[email protected]> > Date: Tuesday, November 11, 2014 10:18 AM > To: Greg Mirsky <[email protected]> > Cc: "[email protected]" <[email protected]> > Subject: [nvo3] 答复: Comments on NVO3 data plane requirements for OAM > > Hi Greg, > > I fully agree with you. > > The real time OAM is passive performance measurement methods. I would like > NVO3 data encapsulation has a field for marking and not affect forwarding > of packets, the marking field is only used for performance measurement. The > NVO3 packet with this marking flag don't need to be sent to control plane, > it is different from OAM(ping/Trace) packet processing. > > Thanks > > weiguo > ------------------------------ > *发件人:* Greg Mirsky [[email protected]] > *发送时间:* 2014年11月12日 4:07 > *收件人:* Haoweiguo > *抄送:* [email protected] > *主题:* Re: [nvo3] Comments on NVO3 data plane requirements for OAM > > Hi Weiguo, > marking groups of packets that belong to the particular flow to > facilitate measurement of some performance metric, whether loss or > delay/delay variation, may be viewed as one of passive performance > measurement methods. But such marking should not alter, at least not > significantly alter, treatment of data flow in the network. Because of > that, I believe, OAM flag should not be used for marking as that will force > punting marked packets from fast forwarding path to the control plane. But > it might be good to have a field in NVO3 header that may be used for > marking and not affect forwarding of packets if altered. > > Regards, > Greg > > On Tue, Nov 11, 2014 at 12:34 AM, Haoweiguo <[email protected]> wrote: > >> Hi All, >> >> I maybe not clearly said in today’s NVO3 meeting, pls allow me to >> reiterate the OAM data plane requirements on the mail list. >> >> Currently NVO3 data plane encapsulation only includes one OAM flag, it is >> used for Ping/Trace similar applications. This kind of OAM application is >> initiated by operators for network connectivity verification, normally when >> network failure occurs. There is another OAM requirements of real time OAM >> or synthesizing OAM. It can be used for packet loss detection in real time. >> When ingress NVE receives traffic from local TS, it gets packet statistics, >> and mark(coloring) the OAM flag relying on local policy when it performs >> NVO3 encapsulation. When egress NVEs receives the traffic, it decapsulates >> NVO3 encapsulation, and gets packet statistics with the real time OAM flag >> marking. By comparing the packet number of ingress NVE and the sum of all >> egress NVEs, packet loss can be deduced. This method can be applicable for >> both unicast and multicast traffic. Local policy on ingress NVE is >> configured by operators or automatically acquired from centralized >> orchestration. >> >> Thanks >> >> weiguo >> >> _______________________________________________ >> nvo3 mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/nvo3 >> >> >
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