I know you can set master/slave clocking when using QSIG PRI.

I have seen it done, I linked a Samsung to Cisco via PRI QSIG, and on the web interface for CM there was an option for master/slave clocking on the PRI, along with coding method (in our case HDB3 and CRC4).

Can't remember where it was as I am the samsung tech not the cisco one, but i was looking over the shoulder of the cisco guy