Cisco 6851 Administration Guide

Step 6 Align the new footstand into the slots in the phone and into the slots in the key expansion module. Press the
footstand firmly in place.
This step ensures that the phone and key expansion module remain connected at all times.
Step 7 Plug the LAN cable into the phone and into the LAN port.
Cisco IP Phone 6800 Series Multiplatform Phones Administration Guide
102
Phone Accessories
Install a Key Expansion Module

Cisco 6851 Specifications

General

Network Protocols	SIP
Speakerphone	Yes
Bluetooth	No
Wi-Fi	No
USB Port	No
Display	3.5 inch grayscale display (396 x 162 pixels)
Ethernet	10/100 Ethernet
PoE	IEEE 802.3af
Audio	Wideband audio
Line Keys	4
Headset Port	RJ9
Supported Codecs	G.711, G.722, G.729, iLBC
Weight	0.9 kg