About TCP sumcheck in GTP

travelping / upg-vpp

User Plane Gateway (UPG) based on VPP

Apache License 2.0

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About TCP sumcheck in GTP #298

Closed PoorProg closed 1 year ago

PoorProg commented 2 years ago

Hello @ivan4th, This NOT issue but question. If the checksum in TCP header is invalid value, does upf drop it? (TCP header is included into GTP)

Best Regards

RoadRunnr commented 1 year ago

I have not checked it, but my gut response would be: "No, why should it?"

A UPF is a middle box that forwards IP packets. Checking the checksum of the IP fragments makes sense, but looking at the higher layer checksums is IMHO not a task for a middle box.

PoorProg commented 1 year ago

Hello, Andreas-san,

Thank for your response! I have checked that a upg-vpp(UPF) does not check TCP checksum by using debug tool . Best Regards

PoorProg commented 1 year ago

This is OK. And I totally agree with Andreas-san's opinion. Thank you very much!