Will the TCP-INT function be added?

[jackmygreat]

In-band telemetry is an important feature, are there plans to add TCP-INT to the code?

[jafingerhut]

Do you mean this code? https://github.com/p4lang/p4app-TCP-INT

[jackmygreat]

This project uses the code from TCP-INT. TCP-INT has a separate p4 code at https://www.intel.com/content/www/us/en/products/network-io/programmable-ethernet-switch/connectivity-education-hub/research-program.html

[jafingerhut]

Sorry, yes I checked after I posted my comment above, and that reminded me that the P4 code for the Tofino part of TCP-INT is not in that repository.

I can ping @pkotikal to see if she knows the answer. I do not know if there are plans to add Tofino TCP-INT P4 code to this, or any other, public repository.

[jackmygreat]

Thank you very much. I have another question. I have a machine with bf-sde9.2 deployed. The TCP_INT code is in bf-sde9.2.1. I found that they are only different in the pkgsrc/switch-p4-16 directory. Can I copy the switch-p4-16 directory of TCP-INT to the current bf-sde9.2 machine, and then only compile switch-p4-16? Because it takes a long time to fully compile SDE.

[jafingerhut]

I do not know for certain, but I'd recommend to try it and see what happens. Also, note that In the time it takes to await an answer, I'd bet your computer could have finished fully compiling another version of the SDE.

[marcosfsch]

@jackmygreat, can you confirm in which path in bf-sde the TCP_INT code is available?

[jackmygreat]

The doc of TCP_INT is in packages/switch-p4-16-9.7.2/docs/tcp-int.md. The P4 code of TCP_INT is in packages/switch-p4-16-9.7.2/p4src/shared/tcp_int.p4. @marcosfsch

[pkotikal]

@jackmygreat, apart from the switch-p4-16 programs included in the latest SDE, we don't have any plans to add old profiles.

[jackmygreat]

As the documentation describes , the switch.p4 program describes a data plane of an L2/L3 switch.

When we run the ./run_switchd.sh -p switch command, we encounter problems when setting routing or forwarding. Our topo is as follows. We try to set the FIB table, but don't know how to set the nexthop_index. So, how should we set FIB table or other things to achieve routing or forwarding? Or is there any relevant example? Thank you very much

[Gold778b]

@jackmygreat I recommend that you familiarize yourself with ready-made examples from Inter in the folder /opt/open-p4studio/pkgsrc/p4-examples/p4_16_programs. There is a python test file in which you can see how to configure chip tables.

[Gold778b]

@jackmygreat In this example, you need to configure a packet forwarding table from input port 1 to output port 2 through the Control Plane.

[jackmygreat]

I have set up the FIB table. The nexthop_index is the D_P number. 148 and 132 are the D_P number. What does nexthop_index mean, does it refer to the port number?

[Gold778b]

22/0 |21/0|148|1/20|10G |NONE|Au|Au|YES|DIS|DWN| NONE | 0| 0|
148 - port 22/0

[jackmygreat]

This is the status of PM.

[Gold778b]

Do you have a virtual switch or a real one? Have you redefined the ports?

[jackmygreat]

real hardware switch

[Gold778b]

Are you using open SDE (open-p4studio)?

[jackmygreat]

I use bf-sde, but its switch.p4 is basically the same as open SDE.

[Gold778b]

@jackmygreat For discount nexthop_index is not the output port number. As far as I understand nexthop_index needs to be associated with the output port.

[Gold778b]

This is roughly how it should be

table nexthop_table {
key = {
meta.nexthop_index: exact;
}
actions = {
forward;
}
}

action forward(bit<9> port) {
standard_metadata.egress_spec = port;
}

apply {
nexthop_table.apply();
}