I have started a project called
open-cgf that should address this need. It is currently still being developed, but does accept and decode GTP' for UDP, and I've just started implementing the other messages. It doesn't decode the ASN.1, but will (shortly) write them to disk in encoded format -- without the GTP' header. Decoding ASN.1 CDRs is another project I'm working on.
Coupled with this is will be a test program to exercise it, which should be useful for people implementing CGF's too...
I will be relying on people to test this and report faults as I cannot test it directly. Traces from an existing model network would be appreciated...
You will need to install
Erlang before you can run the CGF -- and I've not yet written the instructions for that either
Development is proceeding quite quickly.
If you want to start using this please drop me a line.