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In this article we'll using freeRouter setup deployed in #003 and replace bmv2/simple_switch_grpc providing freeRouter P4Lang's dataplane by INTEL BAREFOOT/bf_switchd. Actually the effective dataplane is ensured by INTEL/BAREFOOT virtual bf_switchd model running RARE P4 program called: bf_router.p4.

Diagram

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#004 ] - Cookbook

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titleInstall your favorite operating system

In our example we will use the OpenNetworkLinux KVM image (ONL9) this is the recommended build from INTEL/BAREFOOT for SDE-9.2.0.

and we add a network interface bridged to or laptop RJ45 connection.

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  • had a demonstration of how to integrate freeRouter into a local area network (Similar to article #002)
  • However instead of using bmv2 we used a INTEL/BAREFOOT P4 dataplane called: TOFINO (bf_switchd)
  • TOFINO bf_switchd target is running RARE bf_router.p4
  • communication between freeRouter control plane and TOFINO is ensured by pcapInt via veth pair [ veth250 - veth251 ]
  • This communication is possible via RARE bf_forwarder.py based on GRPC P4Lang BfRuntime python binding
  • In this example the TOFINO bf_switchd P4 virtual switch model has only 1 dataplane interface that is bound to enp0s3 VM interface exposed to the local network as a bridged interface
Tip
title[ #003 #004 ] RARE/FreeRouter-101 - key take-away
  • FreeRouter is using UNIX socket in order to forward packet dedicated to control plane + dataplane communication.

This essential paradigm is used to ensure communication between freeRouter and TOFINO bf_switchd P4 dataplane. It is ensured by pcapInt binary from freeRouter net-tools that will bind freeRouter socket (veth251@locathost:22710) to a virtual network interface (veth250@localhost:22709)  connected to CPU_PORT 64.

  • freeRouter control plane and dataplane communication is enabled by RARE bf_forwarder.py 

bf_forwarder.py is a simple python script based on GRPC client BfRuntime python library.

freeRouter is doing all the control plane route computation and write/modify/remove message entry via BfRuntime so that P4 entries are created/modified/removed accordingly from P4 tables

While TOFINO bf_switchd virtual model target is a very good choice for packet processing algorithm validation on TOFINO platform, the virtual model is not a target for production use. We will see in next articles how we can reach TREMENDOUS traffic throughput required by Internet Service Provider's use cases. Indeed, while with the model we can validate algorithm accuracy, traffic transfers achieved have a very low throughput. (I could barely make my setup described above working)

In a subsequent article we will demonstrate how we can create with RARE/freeRouter/TOFINO TNA architecture, a service provider/carrier grade router that technically is able to switch 3.3 Tbps of traffic (line rate) using EdgeCore WEDGE100BF32X hardware switch.

Note

TOFINO NPU family most powerful NPU has the ability to switch 6.5 Tbps traffic throughput, our WEDGE100BF32X switches are powered by the NPU little brother that is able to handle 3.3 Tbps line rate traffic throughput.


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