There is not a single post of you that included all the information, like: * tty output of "bs11_config dump" of both the BTS * tty output of "bs11_config" regarding the A-bis link state of both BTS * detailed list of the procedures that you have already tried, like switching rx/tx wires * detailed explanation how you have configured mISDN and the hfcmulti driver to run multiple d-channels on one E1 link, i.e. applying linux-2.6.30-hfcmulti-multibts.patch and specifying the correct module parameters
If you really want to enable us to help you properly, please make sure you are as detailed and as verbose as possible!