cisco phone model 8851 manual

The Cisco IP Phone 8851 is a high-quality, full-featured VoIP desk phone designed for business environments. It features a high-resolution color display, support for up to 10 lines, Gigabit Ethernet, Power over Ethernet (PoE), integrated Bluetooth, and advanced audio capabilities. This manual covers key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Devices 7. Using Phone Features 8. Accessibility Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: High-resolution color display, Handset, Speakerphone, Keypad, Ethernet ports, Headset port.

Feature	Description
Display	High-resolution color LCD with backlight
Network Ports	Gigabit Ethernet (10/100/1000) with PoE support
Audio	HD Voice, Wideband audio, Acoustic echo cancellation
Bluetooth	Integrated for headset connectivity
Headset Port	3.5mm jack for wired headset
Line Keys	Up to 10 programmable line/speed-dial keys
Power	Power over Ethernet (PoE) or external power adapter
Security	802.1X authentication, encrypted signaling
Protocols	SIP, SCCP support
Mounting	Desk mount and optional wall mount

Installation

Unpack and inspect contents. Place phone on stable surface.

Connect to Network: Plug Ethernet cable from switch into phone's NETWORK port.
Connect PC (Optional): Plug Ethernet cable from phone's PC port to computer.
Connect Handset: Plug handset cord into HANDSET port.
Connect Headset (Optional): Plug into HEADSET port.
Apply Power: Use PoE from switch or connect external power adapter.

WARNING! Use only approved power adapter. Ensure cables are securely connected.

First-Time Setup

Power on phone; follow on-screen prompts.

Network Boot: Phone will obtain IP address via DHCP.
Firmware Upgrade: Phone may download firmware from TFTP server.
Configuration: Phone will download configuration from call control server.
Registration: Phone registers with call control system (CUCM or other).
Verify Operation: Check for dial tone and test call.

CAUTION! Do not unplug phone during firmware upgrade.

Specifications

Display: 5-inch color LCD, 800 x 480 resolution.
Network: 10/100/1000 Mbps Ethernet, IEEE 802.3af PoE.
Audio Codecs: G.711, G.722, G.729, iLBC, Opus.
Bluetooth: Version 4.1, HSP and HFP profiles.
Protocol Support: SIP (Session Initiation Protocol), SCCP (Skinny).
Security: 802.1X, TLS, SRTP.
Power: PoE (Class 3) or 48V DC external adapter.
Operating Temp: 32°F to 104°F (0°C to 40°C).
Dimensions: 9.0" x 10.0" x 6.5" (229 mm x 254 mm x 165 mm).

Controls and Settings

Access settings via phone's touch screen or physical buttons.

Physical Controls: Mute, Speakerphone, Volume rocker, Navigation cluster, Soft keys, Hold, Transfer, Conference, Headset, Messages, Settings.

On-Screen Settings: Network configuration, Audio settings (ringer, speaker, handset volume), Display settings (contrast, backlight), Phone information (model, MAC, IP), Bluetooth pairing, User preferences (language, time format).

Administrator Settings: Accessed via web interface (phone's IP address) for advanced network and security configuration.

Connecting Devices

Network: Ethernet cable to NETWORK port. PC: Ethernet cable to PC port. Audio: Handset, headset, Bluetooth headset.

Turn off phone before connecting new devices if possible.
Match cables to correct ports.
For Bluetooth: Enable Bluetooth in phone settings, put headset in pairing mode, select from phone's discovered devices list.

Tip: Use Cat5e or better Ethernet cables for Gigabit performance.

Using Phone Features

Supports basic and advanced telephony features.

Making Calls: Lift handset or press Speakerphone, dial number, press Dial soft key.
Answering Calls: Lift handset, press Answer soft key, or press Speakerphone.
Hold: Press Hold button during active call.
Transfer: During call, press Transfer, dial target number, press Transfer again.
Conference: During call, press Conference, dial second party, press Conference again to merge.
Voicemail: Press Messages button, follow prompts.
Speed Dial: Program speed-dial numbers via web interface or phone settings.
Call History: Press Navigation button to access missed, received, and placed calls.

WARNING! Do not expose phone to liquids. Keep ventilation openings clear.

Accessibility Features

Visual Alert: Flashing LED for incoming calls. Audio Adjustments: Independent volume controls for ringer, handset, speaker. High-Contrast Display: Adjustable display settings for improved visibility. Hearing Aid Compatible: Handset is hearing aid compatible (HAC).

Care & Cleaning

Unplug power before cleaning. Use slightly damp, lint-free cloth. Do not use abrasive cleaners or sprays.

CAUTION! Do not allow moisture to enter openings. Avoid direct sunlight and heat sources.

Regulatory Information

FCC Part 15: Class A digital device; complies with limits for business use. ICES-003: Complies with Canadian EMI regulations. CE Mark: Complies with European directives. Copyright © Cisco Systems, Inc. All rights reserved. For support, visit www.cisco.com or contact Cisco Technical Assistance Center.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Power source	Check PoE switch or power adapter connection; try different cable.
No network connectivity	Cable/DHCP	Check Ethernet cable; verify switch port; check DHCP server.
No dial tone	Registration	Check phone registration status on call server; reboot phone.
Poor audio quality	Network/Codec	Check network for packet loss/jitter; verify codec configuration.
Bluetooth not connecting	Pairing/Settings	Ensure Bluetooth enabled on phone; put headset in pairing mode; re-pair.
Display issues	Settings/Cable	Adjust display settings; ensure display cable is secure internally (requires technician).

Reset: Press and hold # key during boot for factory reset (erases all settings).

Service: Contact network administrator or Cisco TAC. Do not attempt internal repairs.