There are no 'national' calling frequencies for "DV" or "DD" in the US. ?You need to find some locals and agree upon one. ?
The nice thing about 23 cm is that in most parts of the country you have wide latitude to pick a frequency.
Here is an example from
Proposed Utah Simplex Frequencies on 23 CM:1298.0 Digital Data Simplex 1 (192.168.98.0/24 network addresses?)
1298.2 Digital Data Simplex 2 (192.168.2.0/24 network addresses?)
1294.6 Digital Voice Simplex
John D. Hays
Amateur Radio Station
PO Box 1223
Edmonds, WA 98020-1223
John Hays - K7VE / WRJT-215