BH Master Vs. Slave Considerations

When setting up a BH link, what are the considerations in deciding which end should be designated as master and which as slave? What difference does it make which is which?

In our case, one end will be connected to a CMM, so I would assume that this should be the Master, so that it can pass sync to the other end. Is this a valid assumption? Or are there other issues I need to consider?

Thank you.

yes, i would put the master bh on the cmm side.