First, this trex tool just rocks!
It took us two days to get up and running for the first time during January 2021. In another two days we got IPv6 working for traffic to test our product. We spent another three days to test number of subscribers for scale.
My company has developed a UPF VPP plugin for 5G that supports both IPv4 and IPv6. Our company has a P4toVPP compiler to generate a VPP plugin. To test the UPF, I use Scapy with Trex to generate a GTPU packet. I don’t need anything else. Then, I used the trex device engine to generate 4k stateless flows for IPv6. I will look into trex for GTPU stateful tests.
Regards,
Hemant