• Packet marking is part of the "SciTags" activity in the Research Network Technical WG.  95 members from 50 orgs.
• Primary goal: allow tracking and correlation of transfers with R&E network provider's network flow monitoring.
  • Can associated flows with a specific experiment or activity.
  • Provides sites with more visibility into network flows.
• How tags works:
  • Packet marking: markers are added to each packet.
  • Flow marking: UDP firefly sent out periodically, associated with the flow.
  • Network-level collectors at the respective entities collect fireflies or examine packets; hook into the respective analytic platforms.
  • See: https://www.scitags.org/api.json
• WLCG:
  • Experiment-level systems have knowledge, pass it to FTS3.
• Status:
  • Flow marking works with IPv6 and IPv4, hence is the focus.
  • XRootD 5.4.0 supports UDP fireflies.
    • N.b. - XRootD docs: https://xrootd.slac.stanford.edu/doc/dev54/xrd_config.htm#_Toc88514010
  • External-to-storage script based on netstat information.
  • ESNet and Jisc/Janet have deployed collectors.
  • Simplified deployment was done during the last data challenge.  Able to correlate UDP fireflies with netflow data.
• Various additional links to the project on the slides.
• Discussion:
  • Does the prototype work with HTTP?  A: Yes (Brian thinks it might not work with HTTP push)
  • Technical discussion - note that the fireflies are only sent at beginning and end?
  • Timeline?  DC2023.
  • Who is onboard?
    • ATLAS is enthusiastic, others are backing / provide interest.
  • What about dCache?
    • Currently used the netstat version.
    • dCache team is aware of the activity but not clear if there's a timeline yet.  ACTION ITEM: Need to get input from Tigran.
  • How are flows marked precisely?  E.g., HTTP headers?  TBD.