Thanks for the reply Jimates.
Unfortunately I cannot use your suggestion. I need to access the Landline on Obi2 and vice versa. This is an annoying situation, because people who are not aware of the call routing behind this setup (most if not all) will tend to call the number they see on their display when they return the call. I guess some other Obi users must face the same problem?
If there is no way to do this via the Obi configuration, then I guess I will have to mask the landline caller id's on both Obi's and configure them in such a way that the caller id is shown if the call is made directly from the Phone port of the concerned Obi. Calls originating from another Obi will, if I understand correctly, ignore the local dialing rules and thus the caller id will be masked.
Can you confirm this? - Obi Support team?
Thanks in advance.