Currently both the Cisco ATA-186 and the Cisco 7960 (with SIP image) are supported products...The Cisco ATA-186 which has been tested with our software costs about US$ 175...
Sometimes you will find a second line on the yellow and black wires, but this is not good practice because, in quad cable, the wire pairs are not twisted together, which can result in "crosstalk" between the two lines...It's a judgment call on whether to replace that wiring — if it is still working and the insulation appears to still be in good condition, with no visible damage,...
BUY Cisco ATA186-I2-A ... Cisco ATA 186 with complex impedance (270 ohm in series with 750 ohm. and 150 ... Protocol (SCCP)-Cisco CallManager technology ...