intercomm system for visitors

[yeow_km]

we have plans to place a phone beside the main door for visitors to contact our colleagues.

can i make use of the call manager to create a intercomm system for visitors to call any internal numbers.

all my users are using 6921 IP phones and our call manager is version 9.

can i just place another 6921 outside the main door for visitors to dial the internal extension number without extra hardware ?

are there special phones model that are mean for intercomm system?

[Leo Laohoo]

Best method is for the phone to dial only ONE number when someone picks it up (like a hotline).  The nominated phone could be the main reception desk.  

Alternatively, you can configure the phone to dial only internal numbers.  Outside numbers, overseas and/or mobile phones will be disabled.