OsBiz internetwork trunk access

[Provax]

Hello dear engineers,

I have two OsBiz that are in internetwork. Each other of OsBiz was connected to some CO trunks.
The internal telephones can call each other in both Osbiz but the internal phone in one OsBiz dosn't have access to Co trunk in other OsBiz. When internal phones of one side PBX dialling Co trunks in other side, the telephone was displayed "Feature not available".
Can you help me to underestand why internal telephones have problem to access to Co trunks in other side?

 

[yayayoyo]

do you have the networking license on both of them !!