AT&T SB67030 Corded Desk Phone Corded desk phone is designed for use with an AT&T DECT 6.0 Digital Business Phone System that runs on your existing Ethernet network and connects to traditional analog outside phone lines. Desk phone can handle up to five calls simultaneously and supports a cordless twin extension. A 5" lighted display has context sensitive softkeys and on-screen help so you can use all of the features: three-party conferencing, Caller ID, 50 name/number phonebooks, call forwarding, call park, do not disturb, 30 minutes of voicemail storage, and speakerphone. Wall-mountable desk phone supports a cordless twin handset and cordless or corded headsets.