Call flows is as follows.PSTN--->Verizon SIP trunk (MPLS Ethernet)--->3750X--->CUBE (2921)--->CUCM (8.0.3 running on 1 pub and 2 subs)---->Remote routers (28xx and 29xx) -->remote switches (3xxx and 2xxx models)--->IP Phone (79xx)CUBE, CUCM, and 3750...