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Meeting Minutes: September 6, 2018

Mukesh Hira edited this page Sep 10, 2018 · 1 revision

Meeting Time and Location

10 am to 11:30 am PDT (GMT - 7), Barefoot Networks, 4750 Patrick Henry Dr, Santa Clara, CA 95054

Attendees

Barefoot Networks: Jeongkeun Lee, Mickey Spiegel, Roberto Mari
Cisco Systems: Ramesh Sivakolundu, Mario Baldi
Princeton University: Muhammad Shahbaz
VMware: Mukesh Hira

We revisited the proposal for domain specific extensions that Ramesh Sivakolundu from Cisco Systems presented at an earlier working group meeting in June. At a high level, the following decisions were made regarding this proposal -

  • D bit in the INT header and Domain Specific Instructions are two separate features and will be addressed separately via two separate edits to the specification.
  • Domain ID and DS Flags will always be present in INT header version 2
  • Bit 14 in instruction bitmap will indicate presence of domain-specific instructions to be executed at each INT hop that supports the domain ID
  • Nodes that don't support the domain ID may either not add any metadata to the packet, or add metadata corresponding to bits 0-13,15 of the base instruction bitmap and reserved value (all ones) for metadata length corresponding to domain specific metadata. Each hop either inserts no metadata or inserts Hop-ML worth of metadata
  • Metadata is to be inserted in the order of bits 0-13 of base instruction bitmap, metadata as per domain ID, followed by checksum complement if bit 15 is set. Checksum complement metadata continues to be the last metadata inserted at each hop

Other Discussions

The meeting time was almost entirely used up in a detailed discussion on domains specific extensions, but the good thing is we did close on open questions around this proposal. In the last 15 minutes, we discussed a some new INT items to be addressed in subsequent meetings -

  • INT over MPLS to allow telemetry over a MPLS Label Switched Path
  • INT metadata for queue occupancy in architectures with shared buffers and dynamic thresholding. If queue occupancy is reported as the number of bytes/cells/packets in the queue, such queue occupancy is well defined. But if queue occupancy is to be reported relative to the queue depth, then shared buffers and dynamic thresholding need to be addressed in such a relative definition of queue occupancy

Next Steps

  • Ramesh and Mickey to edit the INT specifications for D bit and domain specific extensions, and send the edits out for review
  • Next working group meeting will be on September 20, 2018. Agenda and location to be announced closer to the date