Cisco Systems, Inc. CP-6851-3PCC-K9= VoIP phone 4 line 396x1262 display

Cisco IP Phone 6851 – 4-line VoIP desk phone

The Cisco IP Phone 6851 is a corded VoIP desk phone built for third-party hosted call control deployments. It provides four programmable line or feature keys, a high-resolution 396 x 1262 pixel display, and wideband audio support. Power over Ethernet Class 2 simplifies cabling, while an integrated Gigabit switch allows a colocated PC to share the network drop. A power-save option reduces consumption during off-hours.

Capacity and headroom: four lines and Gigabit

Four programmable keys handle four simultaneous lines or feature assignments, suiting typical knowledge-worker and front-desk roles. The integrated two-port Gigabit switch passes full line-rate traffic to a PC, so the phone does not become a network bottleneck. The 396 x 1262 pixel display renders call information and XML applications clearly. Headset and Electronic Hookswitch ports support hands-free operation, but the handset cord and lack of wireless radios limit mobility to the desk.

Upgrade path: replacing legacy analogue

This phone replaces analogue handsets or older single-line IP models that lack PoE, Gigabit passthrough, or wideband audio. The jump is worth it when a hosted platform requires encrypted SIP signalling, XML browser apps, or a power-save schedule to meet energy policies. Buyers needing more than four line appearances, colour touchscreens, Bluetooth, Wi-Fi, or video calling will need a different product tier.