The Cisco ATA 188 Analog Telephone Adaptor interfaces regular telephones with IP-based telephony networks. The Cisco Analog Telephone Adaptor products are standards-based communication devices that deliver true, next-generation voice-over-IP (VoIP) terminations to businesses and residences worldwide. These products address the needs of enterprise companies, small-office environments, and the emerging VoIP managed voice services and local services market by helping companies to cost-effectively turn their analog telephones into IP devices. The newest member of the Cisco ATA product family, the Cisco ATA 188, provides added connectivity, features, and ease of administration.The ATA188-I2 is Cisco ATA 188 2-port adaptor with switch, complex impedance (270 ohm in series with 750 ohm and 150 nF in parallel).