Re: [nvo3] Comments on draft-ietf-nvo3-vxlan-gpe

Greg,

You seem to be confusing and mixing things up.

Please see inline.

> On Apr 12, 2019, at 2:50 AM, Greg Mirsky <gregimirsky@gmail.com> wrote:
> 
> Dear Editors, et al.,
> I've read the latest -07 version and would like to share my comments and questions with you:
> 	• in the earlier version of the draft, the O-bit was introduced and defined as:
> OAM Flag Bit (O bit):  The O bit is set to indicate that the packet is an OAM packet.
> At the same time, in the latest version, the new Next Protocol value (0x81) to identify iOAM Data was introduced. Hence are my questions:
> 	• What must be the value of the O-bit when the value of the Next Protocol field is iOAM?

The O bit “is set to indicate that the packet is an OAM packet”.
IAOM is not an OAM packet. Hence, O bit clear if VXLAN-GPE encapsulates a non-OAM packet and adds an IOAM shim.

> 	• Do you plan to define the Next Protocol values for active OAM protocols, e.g., Echo Request/Reply, BFD, Performance Monitoring?

I cannot speak to “plans” (replying as “et al.”, not as “editor”), but I expect OAM documents ought to have those requested, and you do not need necessarily all of those — the nex protocol IPv4 / IPv6 can encapsulate ICMP, UDP/BFD, etc., etc., etc., etc.

> 	• How to interpret the situation when the O-bit value is 1 but the value of the Next Protocol field is, for example, NSH, i.e.., not any of OAM protocols?

I expect it means there’s OAM within that NSH (sometimes there’s no such things as “OAM Protocols”), or an unhandled OAM protocol.

> 	• I believe that the use of the dedicated OAM flag and the Next Protocol field for a fixed-size header that cannot include meta-data is unwarranted and adds unnecessary complexity.

Disagree. 

See example where protocol is IP carrying an OAM packet.

> I suggest not to use O-bit in the VXLAN-GPE header and release it into the Reserved field.  I don't see the apparent benefit of using the flag, as the VXLA-GPE uses the fixed size header and the header cannot carry OAM data in it. The only role the VXLAN-GPE header must perform, in my opinion, is to unambiguously identify the payload type that immediately follows the header as OAM (demultiplexing OAM protocols may be done in OAM Header shim).
> Much appreciate your consideration.
> 

Best,

—
Carlos Pignataro, carlos@cisco.com

“Sometimes I use big words that I do not fully understand, to make myself sound more photosynthesis."

> Regards,
> Greg
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