Does anyone know if it is possible for an outside caller to dial in and page over the intercom system? if not, any other suggestion?
the system is a merlin Legend r7

NO, I don't think it can be done. Why would you want someone from outside your company to be able to page over your system? Explain what you are trying to do. I think it would be best for the caller to go to a person inside and let them do the paging.

Yes, you have to udp a extension that go's to the paging trunk. In the route delete the digits going out. Everyone will have to page this way. You can use the ARS level to control who can page and also remote access.

GKAR -- thanks for the post; I did not know you could do that. When you say that everyone will have to page like that -- are you talking about on site paging too. Also how do you set up a extension to the paging trunk?

Dial the extension. The extension is not local to the dialplan and will route to the pool that contains the paging trunk.