On Tue, Aug 9, 2016 at 12:02 PM, Carlos Pignataro (cpignata) <cpign...@cisco.com> wrote: > >> On Aug 9, 2016, at 12:28 PM, Tom Herbert <t...@herbertland.com> wrote: >> >> On Tue, Aug 9, 2016 at 9:07 AM, Greg Mirsky <gregimir...@gmail.com> wrote: >>> Hi Tom, >>> many thanks for the most informative response. I've added mu notes in-line >>> under tag GIM>>. >>> >>> Regards, Greg >>> >>> On Mon, Aug 8, 2016 at 5:44 PM, Tom Herbert <t...@herbertland.com> wrote: >>>> >>>> On Sun, Aug 7, 2016 at 7:02 PM, Greg Mirsky <gregimir...@gmail.com> wrote: >>>>> Dear Authors of the VxLAN-GPE, GUE, and GENEVE, >>>>> all protocols under consideration use a bit flag rather than explicit >>>>> protocol type to indicate that payload is a test packet, i.e. active >>>>> OAM. >>>>> I'm trying to understand the rationale of such decision. Does use of the >>>>> bit >>>>> flag rather than protocol type produce more efficient implementation, is >>>>> more HW friendly? In GUE, the the field to indicate type of the payload >>>>> even >>>>> tagged Proto/ctype as its interpretation depends upon value of the C >>>>> bit. >>>> >>>> The C-bit in GUE distinguishes data messages from control >>>> messages.Data messages are considered to be the payload of >>>> encapsulation, whereas control messages are about the encapsulation >>>> itself. OAM might be one type of control message in GUE, however there >>>> could be others. For instance if we wanted some sort of negotiation >>>> between two endpoints to exchange capabilities or supported features >>>> this would fit well into a control message. >>> >>> GIM>> Yes, what I've proposed is clearly more than just OAM channel. In >>> fact, it is Associated Channel (ACh) that may be used by control, management >>> and OAM. And as I've used term "Associated Channel" you'll easily recognize >>> that I have MPLS background and draw on MPLS/MPLS-TP OAM experience. And as >>> Generic ACh (G-ACh) is used to advertise capabilities of an LSR in RFC 7212, >>> AC-h in NVO3 can support similar functionalities as well. >>>> >>>> >>>>> But wouldn't it be simpler if all proposals used protocol type to >>>>> identify >>>>> OAM payload? And if the protocol type is OAM, then after the protocol >>>>> header >>>>> have OOAM Header, e.g. as proposed in . Then >>>> >>>> Each of the three protocols has a protocol next header field, however >>>> the field is defined differently among them. The next header in GUE is >>>> an IP protocol number, in Geneve it is an Ethertype, and VXLAN-GPE >>>> uses a new number space. In GUE we could probably use ICMP protocol >>>> for OAM by defining the appropriate types (that might have the >>>> advantage of allow OAM to be generic instead of restricted to only >>>> encapsulation). Presumably, VXLAN-GPE could define some value in the >>>> number space for for OAM. For Geneve maybe there is an appropriate >>>> Ethertype? >>>> >>>>> NVO3 protocols would be able to have common Active OAM (Fault Management >>>>> and >>>>> Performance Measurement) that can be used in BIER and SFC. And the bit, >>>>> the >>>>> bit I'd propose to redefine to be used for passive performance >>>>> measurement >>>>> as described in draft-ietf-bier-pmmm-oam. (Allocating two bits-long >>>>> field >>>>> would enable more accurate measurements using the Alternate Marking >>>>> method). >>>>> And these steps will enable us to develop common Active OAM and use >>>>> passive >>>>> performance measurement regardless, almost, of the data plane protocol >>>>> used >>>>> in NVO layer. >>>> >>>> The problem I see with trying to constrain the solution to only one or >>>> two bits of information is that this substantially limits the >>>> functionality. With an extensible protocol we should be able more >>>> information to get more accurate measurement. For instance, I might >>>> want to measure the latency of individual packets to get feedback on >>>> path selection, correlate performance to packet loss, etc. Has the OAM >>>> DT considered the requirements and solutions for passive performance >>>> measurement? >>> >>> GIM>> Indeed, the OAM DT had considered the requirements to enable use of >>> performance measurement methods as passive OAM. Should note that we use term >>> "passive method" somewhat differently from the definition in RFC 7799. Such >>> interpretation was discussed in the IPPM WG and we've agreed that if a >>> measurement method does not change treatment of a data packet by the network >>> (e.g. doesn't change its CoS, length or else), then the method behaves as >>> close as passive and may be characterized as such. Measurements for a single >>> packet are possible using the Alternate Marking method with two bits-long >>> marker. The draft in BIER WG has such example. I've attached the >>> presentation slides. Will be glad to answer any further questions. >> >> Yes, but number of specific packets I could measure is still limited >> in some time quantum with the two bit method. Alternatively, if every >> packet contained a timestamp for instance, then we can measure every >> packet and filter or aggregate the measurements with arbitrary >> granularity of our choosing. > > Indeed, as for example at draft-brockners-inband-oam-data-01. This is a > measurement that is neither “active” nor “passive” based on the IETF > definitions (where active means a probe, and passive means no change > whatsoever to a packet). > Carlos,
Thanks for the pointer, that looks like a good basis for an extensible and generic OAM inband measurement mechanism. I assume for IPv6 this would be appropriate as options in HBH extension headers, have you defined the formats for that? Thanks, Tom >> BIER may have been defined with as a >> fixed length header so that a couple of bits are all that could >> feasibly be allocated to OAM, but this is not necessarily true for >> other encapsulation protocols that are purposely extensible to support >> a richer set of features. > > Agreed as well. > > Thanks, > > — Carlos. > >> >> Tom >> >>>> >>>> >>>> Thanks, >>>> Tom >>>> >>>>> >>>>> Regards, Greg >>>>> >>>>> On Fri, Jul 29, 2016 at 8:13 AM, Alia Atlas <akat...@gmail.com> wrote: >>>>>> >>>>>> I'd like to have people focus on the key point of this thread. >>>>>> >>>>>> Are there serious technical objections (and specifically what are they) >>>>>> to >>>>>> moving forward with VXLAN-GPE as the standards-track protocol? >>>>>> >>>>>> Are there serious technical objections (and specifically what are they) >>>>>> to >>>>>> moving forward with GENEVE as the standards-track protocol? >>>>>> >>>>>> Are there serious technical objections (and specifically what are they) >>>>>> to >>>>>> moving forward with GUE as the standards-track protocol? >>>>>> >>>>>> We need to capture any relevant objections. So far, there's been some >>>>>> discussion on extensibility - with Tom Herbert providing concrete >>>>>> concerns. >>>>>> >>>>>> I have concluded that almost all the authors would prefer to have no >>>>>> standards track solution if they can't guarantee that theirs is that >>>>>> standard. >>>>>> >>>>>> I do hear concerns about whether a decision will be too late. I think >>>>>> that a decision can only be helpful. It goes back to when is the best >>>>>> time >>>>>> to plant a tree - with the answer of 20 years ago or now. >>>>>> >>>>>> Regards, >>>>>> Alia >>>>>> >>>>>> >>>>>> On Fri, Jul 29, 2016 at 4:34 AM, Naoki Matsuhira >>>>>> <matsuh...@jp.fujitsu.com> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 2016/07/21 23:56, Bocci, Matthew (Nokia - GB) wrote: >>>>>>>> >>>>>>>> WG >>>>>>>> >>>>>>>> There was a discussion in the NVO3 WG meeting in Berlin following >>>>>>>> strong >>>>>>>> advice from our Area Director that we need to come to a consensus on >>>>>>>> converging on a common encapsulation. Two sets of questions were >>>>>>>> asked: >>>>>>>> (1) Should the WG move forward with one standards track encap? >>>>>>>> (2) For a given encap, do you have significant technical objections? >>>>>>> >>>>>>> >>>>>>> I want to inform to this mailing list that I proposed ME6E-FP and >>>>>>> ME6E-PR >>>>>>> at the yokohama meeting. I also have proposal M46E-FP and M46E-PR >>>>>>> (past >>>>>>> called SA46T). >>>>>>> >>>>>>> These encapsulation technologies are based on address mapping. ME6E >>>>>>> use >>>>>>> IPv6 address which mapping MAC address, and M46E use IPv6 address >>>>>>> which >>>>>>> mapping IPv4 address. >>>>>>> >>>>>>> I understand too many encapsulation technologies, however these my >>>>>>> proposal are simple, and may contribute to the Internet. >>>>>>> >>>>>>> I believe address mapping approach is unique, so I want to propose >>>>>>> again. >>>>>>> >>>>>>> sorry not the answer to the question. >>>>>>> >>>>>>> Naoki Matsuhira >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> nvo3 mailing list >>>>>>> nvo3@ietf.org >>>>>>> https://www.ietf.org/mailman/listinfo/nvo3 >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> nvo3 mailing list >>>>>> nvo3@ietf.org >>>>>> https://www.ietf.org/mailman/listinfo/nvo3 >>>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> nvo3 mailing list >>>>> nvo3@ietf.org >>>>> https://www.ietf.org/mailman/listinfo/nvo3 >>>>> >>> >>> >> >> _______________________________________________ >> Rtg-ooam-dt mailing list >> rtg-ooam...@ietf.org >> https://www.ietf.org/mailman/listinfo/rtg-ooam-dt > _______________________________________________ nvo3 mailing list nvo3@ietf.org https://www.ietf.org/mailman/listinfo/nvo3
