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The Cisco IP Phone 8851 combines an ergonomic design with wideband audio for clear voice communications, "always-on" reliability, encrypted voice communications to enhance security, and access to a comprehensive suite of unified communication features from Cisco on-premises and hosted infrastructure platforms. It is also supported on third party hosted call control services.
In addition, Cisco Intelligent Proximity brings the worlds of desk and mobile together for you when you are using your mobile device at the desk for your work. You can move the audio path over to the Cisco IP Phone 8851 during active mobile calls to take advantage of its improved audio acoustics. An example would be to share a conversation with a colleague who you want to listen in. This capability gives you greater flexibility and a superior user experience when at your desk.
The IP Phone 8851 also comes standard with a USB port so you can charge your smartphone when at your desk, and stay connected when away from your desk.
The Cisco IP Phone 8851 offers five programmable line keys. You can configure keys to support either multiple directory numbers or calling features such as speed dial. You can also boost productivity by handling multiple calls for each directory number using the multicall-per-line feature. Fixed-function keys give you one-touch access to applications, messaging, directory, as well as often-used calling features such as hold/resume, transfer, and conference. A five-way navigation cluster helps you transition through menus more easily. Backlit acoustic keys provide flexibility for audio path selection and switching.
Session Initiation Protocol (SIP) for signaling
Session Description Protocol (SDP)
IPv4 and IPv6
User Datagram Protocol (UDP) (used only for Real-Time Transport Protocol [RTP] streams)
Dynamic Host Configuration Protocol (DHCP) client or static configuration
Gratuitous Address Resolution Protocol (GARP)
Domain Name System (DNS)
Trivial File Transfer Protocol (TFTP)
Secure Hypertext Transfer Protocol (HTTPS)
Real-Time Transport Protocol (RTP)
Real-Time Control Protocol (RTCP)
Cisco Peer-to-Peer Distribution Protocol (PPDP)
Cisco Discovery Protocol
LLDP (including LLDP-MED)
Switch speed auto-negotiation
Secure credential storage
Configuration file authentication and encryption
Random bit generation
Hardware cryptographic acceleration
Certificate Authority Proxy Function (CAPF)
Manufacturer-Installed Certificates (MIC)
Locally Significant Certificates (LSC)
Ethernet 802.1x supplicant options: Extensible Authentication Protocol-Flexible Authentication via Secure Tunneling (EAP-FAST) and Extensible Authentication Protocol-Transport Layer Security (EAP-TLS)
Signaling authentication and encryption using TLS
Media authentication and encryption using SRTP
HTTPS for client and server
Secure Shell (SSH) Protocol server
Secure Sockets Later (SSL)-based VPN client
In the Box
Cisco 8851 Wall Mountable IP Phone - White
Limited 1-Year Manufacturer Warranty
Table of Contents
G.711 a-law and mu-law
Internet Low Bitrate Codec (iLBC)
Internet Speech Audio Codec (iSAC)
You can control the hookswitch electronically with a third-party headset connected to either the USB port or auxiliary port, or directly paired with the phone through Bluetooth.
Cisco Intelligent Proximity
Audio path moving sends audio through the IP Phone 8851 for a mobile device-connected call.
Call history synchronization allows you to view placed and missed calls of your mobile device from the IP Phone 8851.
Contact synchronization allows you to synchronize the contact objects from your mobile device to your IP Phone 8851.
QoS (Quality of Service)
The phone supports Cisco Discovery Protocol and 802.1Q/p standards, and can be configured with an 801.1Q VLAN header containing the VLAN ID overrides configured by the Admin VLAN ID.
Temperature & Humidity
Operating Temperature: 32 to 104°F / 0 to 40°C
Non-Operating Temperature: 14 to 140°F / -10 to 60°C
Operating Humidity: 10 to 90% non-condensing
Non-Operating Humidity: 10 to 95% non-condensing
Arabic (Arabic Area)
Chinese (Hong Kong)
Czech (Czech Republic)
English (United Kingdom)
Korean (Korea Republic)
Russian (Russian Federation)
Serbian (Republic of Serbia)
Serbian (Republic of Montenegro)
Certification and Compliance
● Regulatory compliance
◦ CE Markings per directives 2004/108/EC and 2006/95/EC
◦ UL 60950 Second Edition
◦ CAN/CSA-C22.2 No. 60950 Second Edition
◦ EN 60950 Second Edition (including A11 & A12)
◦ IEC 60950 Second Edition (including A11 & A12)
◦ AS/NZS 60950
● EMC - Emissions
◦ 47CFR Part 15 (CFR 47) Class B
◦ AS/NZS CISPR22 Class B
◦ CISPR22: 2005 w/Amendment 1: 2005 Class B
◦ EN55022: 2006 w/Amendment 1: 2007 Class B
◦ ICES003 Class B
◦ VCCI Class B
◦ KN22 Class B
● EMC - Immunity
◦ Armadillo Light
◦ FCC Part 68 HAC
◦ AS/ACIF S004
◦ AS/ACIF S040
◦ NZ PTC 220
◦ Industry Standards: TIA 810 and TIA 920
◦ Industry Standards: IEEE 802.3 Ethernet, IEEE 802.3af and 802.3at
◦ Korea (RRA Public Notification 2010-36, Nov 01, 2010)
◦ Korea (RRA Announce 2011-2, Feb 28, 2011)
◦ FCC Part 2.1093 (BT RF Exposure TR)
◦ RSS-102 (BT RF Exposure TR)
◦ EN 300.328
◦ EN50385 (BT RF Exposure TR)
◦ EN 301-489-1
◦ EN 301-489-17
◦ NCC LP0002
◦ Korea (RRL No. 2006-128, RRL No. 2006-129)
◦ Japan Bluetooth GFSK/EDR