[nvo3] Follow up on draft-tissa-nvo3-oam-fm

["Tissa Senevirathne (tsenevir)" <[e-mail]>]

There was a question on why payload sample is needed in OAM.

Firstly it is an optional field and not always required.

It is expected to be useful when using L2VNI + L3VNI at the same NVE to provide L3 gateway services to clients on L2VNI. Reference is draft-ietf-nvo3-dataplane-requirements-02, section 3.2.2 second last paragraph, please see below section for reference. At the L2VNI/L3VNI GW the sample payload is needed to make the ECMP path selection on the next domain (i.e L3VNI when L2VNI to L3VNI and vise versa).

Reference second last paragraph of section 3.2.2 of draft-ietf-nvo3-dataplane-requirements-02
"       L2 and L3 VNIs can be deployed in isolation or in combination to
       optimize traffic flows per tenant across the overlay network. For
       example, an L2 VNI may be configured across a number of NVEs to
       offer L2 multi-point service connectivity while a L3 VNI can be co-
       located to offer local routing capabilities and gateway
       functionality. In addition, integrated routing and bridging per
       tenant MAY be supported on an NVE. An instantiation of such service
       may be realized by interconnecting an L2 VNI as access to an L3 VNI
       on the NVE."