IPBXs with GXW4502

#1

I have 2units grandstream UCM6208 IPBXs and also Gateway GXW4502 for E1 digital connection placed on separate floors in the same building so there could be physical cabling from floor A to floor b even though they are on separate network (firewall)
pls i need to know what method of network setting on the GXW4502 should be made either SWITCH, ROute or DUAL, so that i could enable the the two network UCMs to have connection to the GXW4502 for E1 link.
kindly reply on this.

#2

This depend on your network not on UCM. Without knowledge about your network topology nobody can answer.
Usually internal go switch.