DASH Workgroup Community Update 2/5/2025

[Kristina Moore]

Hello DASH Community –thank you for your time this week.   

In brief, we had @Riff Jiang from MSFT present the super-interesting Floating NIC Pipeline and packet processing in PR655.  This was a comprehensive presentation with Q&A throughout; please see full notes below for more details.  We will keep this PR open for a week or so to invite comments/contributions, so please feel free to do so in the DASH GitHub repository.  Also,  @Satya Valli Rama from TCS has now been assigned to tackle Issue 38 re: northbound gNMI mapping to SAI – thank you TCS!  We will also find future time to discuss both Redirect Map, and Intel will discuss the open-sourcing of P4 for Tofino.

FNIC snips from DASH repo

 

In Summary (full list below), since the last Community call we have:
   3 PRs/Issues completed (+1)
   9 in ToDo (+/- 0)
   3 in Draft (+1)
   20 in Progress (+1)
   6 Awaiting Review (+1)

For further reading, see full meeting notes and follow-ups below in this thread. 

Just a reminder that we would encourage/invite Community members to present to the Community (test runs or progress, new scenarios, etc…), just ‘r’ to let me know, or generate a PR in the repo.

Follow-up tasks:

• LF Username Transition: Send out a note for DASH Community to join the Linux Foundation mail list (Kristina)
• Floating NIC PR655
• Local Region ID: Merge the update to include the local region ID change after passing all checks
• Smart Switch Related Tables: Resolve the conflict related to adding Smart Switch related tables once the HLD is completed. (Oleksandr)
• PTF Test Cases for DASH Flow: Review the PTF test cases for DASH flow (Riff)
• Underlay TTL and HA Session Parameter: Lower priority, however we should update the documentation to clarify the behavior of the HA session parameter Bounce Back IP. (Marian)
• Dependency Issue for SAI API: Investigate and resolve the dependency issue causing problems for the SAI API upgrade. (Riff)
• Blocking Issue Clarification: Discuss and clarify the blocking issue related to the SAI API upgrade with Mukesh
• Override VM MAC PR Update: Check and update the PR to clarify the behavior of setting the Source Overlay MAC (Marian)
• Independent DPU Upgrade HLD PR 1906: Review the draft of the independent DPU upgrade high-level design. (Team)
• Smart Switch HA Topology Presentation: Arrange for someone to present on the HA topology. (Kristina)
• Redirect Map Discussion: Postpone the redirect map discussion until the HLD is fully ready and provide updates. (Riff)
• Meeting Schedule Adjustment: Consider scheduling three meetings a month at the normal time and one meeting in a time zone-friendly slot for participants (Kristina)

 

Thank you for your time/contributions – see you on 2/12/2025

With respect to any of our DASH meetings  - Community (Wednesdays), or Behavioral Model (Thursdays) – please let me know if there are PRs, Q&A, or items you would like to discuss or present. 
The DASH YouTube channel link is here to subscribe / access WG content (and click the bell to receive notifications). 

               

Meeting Title:  SONiC-DASH-Workgroup Community Meeting #138

Attendees (19):

DASH Group to join: https://groups.google.com/g/sonic-dash     

DASH-Test-Workgroup Group to join: https://groups.google.com/g/sonic-dash-test-workgroup

Linux Foundation list: https://lists.sonicfoundation.dev/g/SONiC-Dash

 

Andy Fingerhut - Cisco	Mahaboob Gani	Oleksandr Ivantsiv - Nvidia	Selvarajan, Arunachalam - AMD
Bud Grise - XSightLabs	Marian Pritsak - Nvidia	Philipp Keydel - Synogate	Swami Balasubramanian - Keysight
Evan Langlais - MSFT	Mircea Dan Gheorghe - Keysight	Prince Sunny - MSFT	Wajahat Razi Malik - XFlowResearch
Kamil Cudnik - MSFT	Mukesh MV - AMD	Riff Jiang - MSFT	Yakiv Huryk - Nvidia
Kristina Moore - MSFT	Murali Venkat - Cisco	Satya Valli Rama - TCS

 

 

 

 

 

TL:DR DASH Community Notes 😊

 

• Provide northbound gNMI/OpenConfig DASH-related schema & mapping to SAI Issue 38: Satya has taken on Issue 38
• Floating NIC (FNIC) Pipeline Presentation by MSFT PR655: Riff presented the Floating NIC pipeline, explaining its importance and how it targets modeling appliances in the cloud network. FNIC allows for more efficient handling of network traffic and improves overall system performance.
• High-Level Workflow: Provided an overview of the high-level workflow of the Floating NIC pipeline, highlighting how it processes packets and integrates with the existing network infrastructure.
• Key Differences: Discussed the key differences between the FNIC pipeline and the regular VM pipeline, emphasizing the unique features and advantages of the FNIC approach.
• Technical Details: Delved into the technical details of the FNIC  pipeline, explaining the specific processes and mechanisms involved in its operation.
• Terminology: Riff clarified the terminology used in the FNIC  pipeline, such as ENI (Elastic Network Interface) and MVA (Multi-Virtual Appliance), to ensure everyone understood the concepts being discussed.
• Packet Processing and Pipeline Design: Riff explained the detailed pipeline design and packet flow, highlighting the differences between the FNIC  pipeline and the regular VM pipeline. He discussed the flow lookup, flow creation, and the stages of the inbound and outbound pipelines.
• Pipeline Design: Provided a comprehensive explanation of the pipeline design, detailing how packets are processed through the FNIC pipeline and the stages involved in the inbound and outbound pipelines.
• Flow Lookup: Discussed the flow lookup process, explaining how the system identifies and processes network flows within the pipeline.
• Flow Creation: Explained the flow creation process, detailing how new flows are established and managed within the pipeline to ensure efficient packet processing.
• Inbound and Outbound Stages: Highlighted the stages of the inbound and outbound pipelines, describing the specific actions and transformations that occur at each stage to handle network traffic effectively.
• Technical Challenges: Addressed some of the technical challenges associated with the pipeline design, including the need for accurate flow management and the handling of complex network scenarios.
• Questions on Packet Processing: Nvidia and Prince sought clarification on tunnel encapsulation and the handling of VM-to-VM communication. Riff provided detailed explanations and confirmed that the destination MAC will be provided by the outbound pipeline.
• Tunnel Encapsulation: Tunnel encapsulation is not performed in the middle of the pipeline, and the packet processing involves logical constructs and metadata handling.
• VM-to-VM Communication: Explained that the destination MAC for VM-to-VM communication is provided by the outbound pipeline, ensuring accurate packet delivery.
• Pipeline Metadata: Confirmed that metadata is passed throughout the pipeline to maintain accurate packet processing and flow management.
• Flow Validation: Clarification on flow validation in the inbound pipeline, with confirmation that  the inbound pipeline performs peer validation to ensure the integrity and security of network flows.
• API and Attribute Changes: Discussed the API and attribute changes required for the pipeline, including the addition of a single attribute to specify if it is a VM or FNIC. Mentioned the need for changes in the VNI direction lookup table and the flow entry.  Changes required in the flow entry including the addition of a single bit to specify the MAC address type.
• Impact of FNIC:  Kristina emphasized the importance of the FNIC  pipeline from a non-developer standpoint, highlighting that it removes the need for VMs and servers behind the DPU, providing improved performance and potential cost savings (in the fact that a VM or server is no longer needed).
• Future Redirect Map Discussion: The Community needs to discuss the redirect map, as it is important for supporting various endpoints like Cosmos, storage, and SQL. Suggested postponing the discussion until the HLD is fully ready.
• Schedule Proposal: Kristina proposed adjusting the meeting schedule to include a time zone-friendly meeting for participants in different regions, suggesting three meetings a month

 

 

 

                             

 

Sticky for Links/Data:
DASH Groups to join to receive Invites, Meeting Notes, and Comms	DASH: https://groups.google.com/g/sonic-dash      DASH-Test-Workgroup Group: https://groups.google.com/g/sonic-dash-test-workgroup   Linux Foundation list: https://lists.sonicfoundation.dev/g/SONiC-Dash	If anyone knows other people who would like info re: our community, please have them joins these groups for receive Comms, etc…
Links to Recording	Teams/Sharepoint: SONiC-DASH Workgroup Community Meeting Wednesday, February 5  DASH Community YouTube: https://youtu.be/NhjrUqh_jcQ  HA moved to SmartSwitch LF group Teams Behavioral Model:  no content this week YouTube Behavioral Model: next week	2/5/2025 DASH Community Call; please request access via the link if you are not able to view/listen
Azure DASH GitHub Repo:	https://github.com/sonic-net/DASH
Test/Docs folder:	https://github.com/sonic-net/DASH/blob/main/test/docs/dash-test-workflow-saithrift.md	Ideal test workflow is here, converted to .md
SAI Thrift	SAI Thrift PR	Client server needed for testing
P4	https://opennetworking.org/p4/ and https://p4.org/working-groups/	Open source, domain-specific programming language for network devices, specifying packet processing for data plane devices (switches, routers, NICs, filters, etc.)
PINS	https://opennetworking.org/pins/
PNA consortium spec	https://p4.org/p4-spec/docs/PNA-v0.5.0.html	An architecture describing the structure and common capabilities of network interface controller (NIC) devices which process packets transiting one or more interfaces and a host system. Describes the structure and capabilities of the pipeline, and a user program, which specifies the functionality of the programmable blocks within that pipeline. For more information, see the P4 Language Consortium specifications
IPDK	Infrastructure Programmer Development Kit (ipdk.io) and https://github.com/ipdk-io/ipdk-io.github.io	IPDK is an open source, vendor agnostic framework of drivers and APIs for infrastructure offload and management which runs on a CPU, IPU, DPU or switch. IPDK runs in Linux and uses a set of well-established tools such as DPDK and P4 to enable network virtualization.
bmv2	https://github.com/p4lang/behavioral-model	The second version of the reference P4 software switch, nicknamed bmv2 (for behavioral model version 2). The software switch is written in C++11. It takes as input a JSON file generated from your P4 program by a P4 compiler and interprets it to implement the packet-processing behavior specified by that P4 program
DPDK	https://www.dpdk.org/	DPDK is the Data Plane Development Kit which consists of libraries to accelerate packet processing workloads running on a wide variety of CPU architectures.
Linux Foundation SmartSwitch	https://lists.sonicfoundation.dev/g/sonic-smartswitch/calendar

 

       

 

Thank you again for your participation…

Kristina Moore MBA, M.S., CISSP - Azure Core Principal PM / DASH & SmartSwitch
Office: 425-722-7720     Mobile: 425-876-2040     Email: kri...@microsoft.com
DASH Group to join: https://groups.google.com/g/sonic-dash    
DASH-Test-Workgroup Group to join: https://groups.google.com/g/sonic-dash-test-workgroup
Linux Foundation:  https://lists.sonicfoundation.dev/g/SONiC-Dash