Guys, I got sys A OS7400 connected via VPN SPNet to sys B OS7400, both able to call ext and can get each others trunks. I connected sys C OS7200. sys C can get sys A trunks but can not get sys B trunks. and sys A and B can get sys C trunks.
It looks quite confusing, but that;s the problem.
Appreciate if anybody can help me to resolve this.

Thank you

Take a look at system c and make sure all your routing digits are there. Also look at your system B and make sure the digit you are using is in the DiD table.

John, sys C routing digits are ok, its throwing correct digits, I can see at smdr. And on sys B DID table not much to play around. It's not deleting incoming digits fro sys C.