If they are PRI's, you need to have the Telco company bundle or bond or tie or whatever term they use the PRI's together. THey will then distribute the inbound calls on each PRI from the LEC to your router.
For outbound, you need configure CCM to use both PRI's for outbound calls. Typically, you would only use one PRI, then when that is full, use the second for "spill over"