Hi Harald,
Can you please also explain how you solved the WAIT_ASSIGN problem as indicated in https://gerrit.osmocom.org/#/c/218/ ? Do you have a specific fix against the bug introduced by the introduction of the WAIT_ASSIGN state?
We have earlier informed in mailing list as well that GPRS issue is likely in one phase access. Hence to avoid this we made a work around by enabling two-phase-access in osmo-pcu.cfg. This work around helps in establishing GPRS call successfully. Due to our current work priorities we have not further investigated root cause of the GPRS one phase access failure.
Thanks, Aravind Sirsikar