in slots virtual cabinet, property of gw16 card. in gw settings tab, set ip address ( the system ip address not dsp)to for both system and note gw number
then in dn2ip tab set the lead number of the systems and select gateway number for that system.
hunt pattern should have the lead number of the other system in it, but can have all numbers 1-9 in here.
setup the gateway trunks in their own trunk group if you dial 7 and extension number it should call it.
to set not to have to dial 7 you will have to change number plan to have opposite sites lead number as other pbx
and in tie table in private network you would set the lead number and remaining number of digits pointing to trunk group of gateway card.
make sure you can ping both ip address of opposite sites.
also make sure you have selected in activation key the number of active ip gateway channels are set to at least 2