Do you already have DS1 circuits in either of these switches, if not do you have the RTUs turned on to support this? Check the system settings with the command 'Display System Customer'. Are these located in the same building or some miles apart? If these switches are located some distance apart have you ordered a circuit(i.e. T1, etc.) and discussed this with the provider? Do you have the DS1 circuit packs with the integrated CSUs or will you be connecting it over a shared network (i.e. data and voice using the same circuit)?