In the previous article #003 "Are you P4 compliant ?" we exposed a setup where RARE/freeRouter was controlling BMv2 P4 dataplane called simple_switch_grpc. In this article we replace the open source BMv2 target by a commercial virtual target provided by INTEL/BAREFOOT. As a side note, we will show that this setup can be integrated with real networks. (with inherent software limitations)
Requirement
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Overview
I'm repeating the core message from #003: For those who are not familiar with data plane programming and especially with P4, "P4 is a domain-specific programming language for specifying the behaviour of the dataplanes of network-forwarding elements." (from p4.org) in short it helps you to write a "program specifying how a switch processes packets".
Article objective
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
[ #004 ] - Cookbook
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 our laptop RJ45 connection.
Verification
Conclusion
In this article you:
- 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
[ #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 the control plane for TOFINO bf_switchd P4 dataplane
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
- TOFINO bf_switchd virtual model target
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)
- TOFINO bf_switchd hardware target
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.
TOFINO family most powerful Programmable Switching ASIC has the ability to switch 6.5 Tbps traffic throughput, our WEDGE100BF32X switches are powered by the ASIC's little brother that is able to handle 3.3 Tbps line rate traffic throughput.