The Cisco DPA Series of voice mail gateways is a family of Voice over IP (VoIP) gateways that enables legacy voice mail equipment to connect to a Cisco IP telephony solution network. The Cisco DPA Series allows Octel voice mail systems—which currently use Digital Station Emulation to connect to an Avaya Definity PBX or a Nortel Meridian 1 PBX—to instead connect to a Cisco CallManager system without any changes to the voice mail system.