Telephone Entry Systems
This system does not require a telephone line as it is integrated into the building telephone network. The tenant requires to have a telephone in the suite. Up front cost are higher, no carrying cost except when a miss wire occures during service.
Telephone Line Based
The lower up front cost and post installation maintenance of the two systems. This type of system does not require the tenant to have a landline, but the lobby unit requires to have a telephone line to dial out.