> On Aug 9, 2016, at 12:28 PM, Tom Herbert <[email protected]> wrote: > > On Tue, Aug 9, 2016 at 9:07 AM, Greg Mirsky <[email protected]> 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 <[email protected]> wrote: >>> >>> On Sun, Aug 7, 2016 at 7:02 PM, Greg Mirsky <[email protected]> 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). > 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 <[email protected]> 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 >>>>> <[email protected]> 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 >>>>>> [email protected] >>>>>> https://www.ietf.org/mailman/listinfo/nvo3 >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> nvo3 mailing list >>>>> [email protected] >>>>> https://www.ietf.org/mailman/listinfo/nvo3 >>>>> >>>> >>>> >>>> _______________________________________________ >>>> nvo3 mailing list >>>> [email protected] >>>> https://www.ietf.org/mailman/listinfo/nvo3 >>>> >> >> > > _______________________________________________ > Rtg-ooam-dt mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/rtg-ooam-dt _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
