# T-rex (No GTPPDUSessionContainer issue)
## ubuntu 18.04
Issue:
NameError: name 'GTPPDUSessionContainer' is not defined
Solution:
Because there's no 'GTPPDUSessionContainer' in t-rex, copy the library from the library of python3.6
```sudo cp /usr/local/lib/python3.6/dist-packages/scapy/contrib/gtp.py /opt/trex/v2.97/external_libs/scapy-2.4.3/scapy/contrib/gtp.py```