PhoneNet was an implementation of the AppleTalk networking physical layer created by Farallon Computing (now Netopia). Instead of using expensive shielded twisted pair wiring as in Apple's LocalTalk implementation, PhoneNet uses standard four-conductor telephone patch cords and modular connectors, and is generally used in a daisy chain topology. PhoneNet used only two of the wires, allowing it to be piggybacked on existing phone cabling by splitting out the wiring in the wall jack into two jacks, one carrying analog telephony via RJ11 jack; the second AppleTalk data via a PhoneNet adaptor. The theoretical maximum speed for data transfer was 230K.
Though PhoneNet transceivers are still available from third parties for use on legacy Macintosh networks, no current Mac model comes with the RS-422 serial ports that are required for PhoneNet transceivers; virtually all Macintosh networking is done using Ethernet or Wi-Fi, with a small amount of IP-over-FireWire used for ad hoc networking.