Intercom to Intercom call blocking

[Tom Clancy]

Dear members i have a query regarding intercom call blocking in ip office.
I have 5xx and 6xx series intercom nos. I want to call from 5xx to 6xx but 6xx will not be able to call to 5xx. Like a tenant group facility. I have done DND activation and DND exception but as the users using DID facility i have to add all the series of mobile, landline nos. which is quite a long process to configure for 100 users. So my question is, is there any other process which i can follow?

Thanks in advance for your kind support.

 

[intrigrant]

No, you can do some tricks to make it harder but full blocking is not possible.
Use two ip office's if it is a mandatory requirement or another brand.