BCM to CS1000 VOIP Network

[vztech]

Sites A,B C,D
A- CS1000 with NRS SIP trunking
B- CS1000 Branch Office SIP
C- BCM400 4.0 SIP & H323
D- BCM50 3.0 H323

all sites register to NRS but I cannot make a private 4 digit call to site D.
Would it be because site D doesnt have SIP ? I thought SIP & H323 could communicate.
If I unregister site D and change site C to direct mode under h323 calls flow from C to D and D to C no problem.

It's only dialtone-VZ

 

[Dasheen]

I believe so. Site D only has h323 trunks and has nothing on the other end to talk to. Explains why when settings changed on site C to H323 u can talk between two sites.