EURO ISDN TBR 4 /CTR 4 Conformance testing

Hi folks,

We are in the process of testing the euro ISDN layer 2 and layer3 and are finding some problems passing the regulatory testing. In particular layer 2. Has anyone successfully gained TBR 4 /CTR 4 certification. Was there any specific configuration required on the asterisk box or the tester.

Best regards