Hi Greg and all, Single bit is not sufficient if someone wants to perform loss and delay measurement simultaneously, then two bits needed.
Best regards, Mach From: nvo3 [mailto:[email protected]] On Behalf Of Greg Mirsky Sent: Wednesday, November 12, 2014 8:05 AM To: Haoweiguo Cc: [email protected]; Larry Kreeger (kreeger) Subject: Re: [nvo3] 答复: Comments on NVO3 data plane requirements for OAM 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]<mailto:[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]<mailto:[email protected]>] 发送时间: 2014年11月12日 4:33 收件人: Haoweiguo; Greg Mirsky 抄送: [email protected]<mailto:[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]<mailto:[email protected]>> Date: Tuesday, November 11, 2014 10:18 AM To: Greg Mirsky <[email protected]<mailto:[email protected]>> Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[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]<mailto:[email protected]>] 发送时间: 2014年11月12日 4:07 收件人: Haoweiguo 抄送: [email protected]<mailto:[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]<mailto:[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]<mailto:[email protected]> https://www.ietf.org/mailman/listinfo/nvo3
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