Cisco CP-9951-K9 (Cisco Unified IP Phone 9951) Full English Datasheet Description

Listing Title

Cisco CP-9951-K9 Unified IP Phone 9951 Premium Enterprise Media VoIP Desk Phone, 5-Line Enterprise Voice, 5-inch 640×480 VGA Backlit Color TFT LCD, HD Wideband G.722 Audio, Full-Duplex Echo-Canceling Speakerphone, Dual 10/100/1000 Gigabit Ethernet Integrated Switch, IEEE 802.3af / 802.3at Class 4 PoE Powered, Dual-Protocol Native SIP + CUCM SCCP Support, Embedded Bluetooth 2.1 LE Radio, Dual Built-In USB Ports (Front + Rear), Optional Detachable USB External VGA Video Camera, Supports Up To 3 Color Key Expansion Modules, Designed For Corporate Executives, Department Managers, High-Traffic Front Desk Receptionists; Flagship Upgrade Over 8900 Series (More Lines, Dual USB, Higher PoE Class, Expandable Up To 3 BLF Modules)

Full Product Overview

The Cisco Unified IP Phone 9951 (CP-9951-K9) is Cisco’s flagship high-end media collaboration desk IP phone within the legacy 9900 Series portfolio, built for executive-level knowledge workers, administrative supervisors, and busy lobby reception stations. It delivers unified enterprise voice, optional real-time VGA video conferencing, customizable expandable BLF key modules, Bluetooth wireless headset integration, and dual USB peripheral support — features that distinguish it from the mid-tier 8900 Series (8941 / 8945) phones.

Core Positioning & Key Differentiators vs 8900 Series (CP-8941 / CP-8945 / CP-8961)

1. 5 independent directory number line keys (8900 Series only 4 lines)for multi-hunt-group reception workloads and executive multi-line deploymentsCisco Russ...
2. Dual USB ports (front accessible USB + rear chassis USB)(8900 Series only zero or single rear USB port) — simultaneous support for USB video camera + USB headset / USB BLF expansion key modulesCisco
3. Higher PoE Class 4 power budget (8900 Series max Class 2 PoE)to fully power dual USB peripherals, Bluetooth radio, video camera, and large backlit LCD without auxiliary AC power adapters
4. Expandable up to 3 separate Cisco Color Key Expansion Modules (8900 Series limited to fewer modules)for dozens of programmable BLF presence monitoring, speed dial, and hunt-group shortcut keys for reception desks and multi-department supervisorsbaynetwork...
5. Optional detachable external USB VGA video camera (SKU CP-9951-CAM-K9) for point-to-point real-time video calling (8941 / 8961 have no integrated video hardware; 8945 has fixed built-in camera with no detachable peripheral option)
6. Identical shared core hardware specs with premium 8900 Series models: 5-inch VGA backlit color touchscreen LCD, HD wideband G.722 audio DSP engine, dual Gigabit Ethernet integrated switch passthrough ports, embedded Bluetooth 2.1 LE wireless headset radio, unified dual SCCP/SIP single-image PhoneOS firmware architecture, full XML enterprise application platform support, and complete ADA accessibility compliance.

Primary Enterprise Deployment Use Cases

• Senior corporate executives, division department managers, executive administrative secretaries, multi-department team supervisors
• High-traffic building lobby / reception front desk stations, multi-line shared hunt-group attendants, call center auxiliary supervisor secondary stations
• Medium-to-large enterprise branch office executive workstations, professional services firm client-facing staff
• Mixed CUCM on-premises unified communications deployments, hybrid CUCM + hosted BroadWorks SIP PBX environments

Hardware & Physical Design Specifications

1. Chassis, Dimensions & Mechanical Build

• Form Factor: Fixed desktop desk phone with dual-position adjustable foot stand (two vertical tilt angles for optimized touchscreen viewing)
• Chassis Material: Thick reinforced ABS polycarbonate textured plastic, two factory color finish options: Charcoal Grey (CP-9951-C-K9) and Arctic White (CP-9951-W-K9), latex-free and recyclable low-carbon construction materials, scratch-resistant front panel coating for continuous 24/7 high-traffic touch interaction
• Standard Handset Variant Total Weight: 1.558 kg (3.43 lb); Slimline lightweight handset alternative SKU available as CP-9951-L-K9 (1.527 kg / 3.37 lb)
• Physical Overall External Dimensions (H × W × D, excluding desktop stand): 234 × 262.5 × 39.7 mm (9.21 × 10.33 × 1.56 inches)Cisco
• Operating Environmental Limits:
  • Working Ambient Temperature Range: -5°C to +55°C (23°F to 131°F)
  • Nonoperating Storage Temperature: -25°C to +70°C (-13°F to 158°F)
  • Relative Humidity Tolerance: 10% to 95% non-condensing atmospheric humidity
  • Altitude Operating Limit: Up to 3,000 m above sea level; storage altitude up to 4,572 mCisco
• Compliance Certifications: ADA American Disabilities Act accessibility standards, MIL-STD-810G basic drop-shock validation for office workplace accidental falls, global EMC/RF safety standards (FCC Part 15 Class B, CE EMC Directive)

2. Front Panel UI, Display & Hard Key Layout

1. 5-inch diagonal fully backlit TFT color touchless LCD display:
   • Native Screen Resolution: 640 × 480 VGA, 16-bit full-color depth, 24-bit Unicode double-byte font rendering for global multi-language localization (Arabic, Hebrew, Simplified/Traditional Chinese, Cyrillic, all European Latin script variants)Cisco
   • Core Display Capabilities: Render full-color caller ID, active call real-time timers, voicemail MWI alert banners, LDAP corporate directory multi-language search results, local persistent call history log archives, customizable user desktop wallpapers, XML enterprise workflow dashboards, real-time VGA video streams from optional external USB camera
2. Dedicated fixed-function hard control keys arranged along the bottom front panel edge: Core universal call control one-touch shortcut keys: Hold, Transfer, Redial, Three-Way Conference Unified vertical rocker toggle key: Single adjustment control for handset receiver audio volume, internal speakerphone output level, and incoming ringtone alert volume
3. Four dynamic context-sensitive horizontal on-screen soft keys with horizontal scroll navigation toggle bar: All call feature options dynamically adapt based on current active call state; scroll bar enables vertical navigation through long directory entry lists, multi-page call history logs, and XML enterprise application menu trees
4. Five vertical side panel independent directory number line keys: Each line key fitted with tri-color LED status indicator light (steady green = established active call, flashing red = incoming ringing alert, steady amber = held call / unread voicemail MWI notification)
5. Dual USB peripheral ports: One front-facing easily accessible USB Type-A port (for quick USB headset or camera connection), one rear chassis USB Type-A port (for permanent USB BLF expansion key module mounting)
6. Backlit tactile numeric alphanumeric dial pad: Standard layout (0–9, *, #) for manual extension dialing, access code entry, voicemail navigation, and XML enterprise application text input.
7. Optional detachable external VGA video camera accessory (SKU CP-9951-CAM-K9): Plugs into any of the phone’s two USB ports, manually rotatable vertical pivot adjustment, mechanical sliding privacy shutter cover to fully block camera lens when video conference calls are not required

3. Audio Subsystem & Supported Voice Codecs

• Handset Receiver: Wideband acoustic driver with adaptive background noise suppression, fully HAC hearing-aid compatible magnetic coupling design meeting ADA accessibility compliance requirements
• Full-Duplex Internal Desktop Speakerphone: Omnidirectional multi-element internal microphone array with built-in digital signal processing (DSP) featuring Acoustic Echo Cancellation (AEC), Background Gain Normalization (BGN), and Automatic Gain Control (AGC) algorithms optimized for busy open-plan executive office and front desk environments
• Audio I/O Interfaces:
  1. RJ-9 four-conductor modular wired headset jack on the left chassis edge for certified enterprise wired headsets, supports EHS electronic hookswitch remote call answer/end control functionality
  2. Integrated Bluetooth 2.1 LE wireless radio for pairing Bluetooth wireless headsets, Bluetooth earpieces, and user smartphones; fully compliant with HFP 1.6 hands-free calling, A2DP 1.3 high-fidelity stereo audio streaming, and PBAP mobile contact list synchronization profiles
  3. Dual built-in USB Type-A ports for direct connection of USB enterprise headsets, USB video camera peripherals, and Cisco USB key BLF expansion modules
• Supported VoIP Audio Codecs (Unified Dual SCCP/SIP Single-Image Firmware): Wideband HD Voice Codec: G.722 (16kHz sampling rate, TIA 920 wideband audio industry compliance standard) Narrowband Codecs: G.711a-law, G.711u-law, G.729a low-bitrate compression codec, G.729ab comfort noise optimized codec, iLBC internet low-bitrate speech codec optimized for lossy cross-campus WAN links
• Supported Video Codecs (Optional External USB Camera Capture & Point-to-Point Video Calling): H.264/AVC video encoding/decoding at fixed 30fps frame rate, native VGA 640×480 resolution video stream rendering on the internal 5-inch LCD touchscreen displayCisco Russ...
• Audio Optimization Feature Suite: Voice Activity Detection (VAD), Comfort Noise Generation (CNG), silence suppression, adaptive full-duplex echo cancellation, intelligent packet loss concealment to eliminate audio stuttering on unstable campus LAN connections

4. Network Connectivity & Gigabit Ethernet Hardware

Dual 10/100/1000BASE-T Gigabit Ethernet Integrated Switch

Two independent RJ-45 8P8C modular Gigabit Ethernet ports arranged in series:

1. Primary LAN Uplink Port: Connects to corporate enterprise access switch, supports dual IEEE 802.3af Class 1 / IEEE 802.3at Class 4 PoE power input (higher Class 4 power budget to fully power dual USB peripheral devices, Bluetooth radio, USB video camera module, and continuous backlit LCD touchscreen operation without separate auxiliary AC power cube adapters)
2. Secondary Downstream PC Passthrough Port: Enables direct connection of a desktop PC or laptop to the corporate LAN without requiring an additional wall Ethernet wall jack, eliminating extra cabling costs for executive office workstation deployments

Supported Network Protocols & QoS Standards

• Layer 2 Discovery & Management: Cisco Discovery Protocol (CDP), LLDP-MED endpoint discovery for IP phone VLAN auto-provisioning and PoE power managementCisco
• Traffic Prioritization & VLAN Tagging: IEEE 802.1p Layer 2 CoS marking, IEEE 802.1Q tagged VLAN segmentation for voice/media traffic isolation from corporate data networks
• Provisioning & Signaling: TFTP zero-touch auto-provisioning for firmware and configuration file downloads, SCCP Skinny Client Control Protocol (CUCM native), SIP Session Initiation Protocol (third-party hosted PBX compatible)
• NAT Traversal: STUN / TURN / ICE NAT traversal mechanisms for remote worker off-site SIP call connectivity

5. Power Supply Architecture

Two separate power input modes for flexible office switch infrastructure compatibility:

1. Primary Power Source: Dual IEEE 802.3af Class 1 / IEEE 802.3at Class 4 PoE power drawn from primary LAN uplink Ethernet port (48 VDC nominal input voltage, Class 4 high-power budget profile to support dual USB peripheral power draw and Bluetooth radio continuous operation)
2. Secondary Backup Power Option: Optional external 48V DC wall-mount AC power cube adapter (sold separately as an accessory SKU, part number CP-PWR-CUBE-3=), universal mains input voltage range 100–240 VAC, 50/60 Hz global regional compatibility

• Power Efficiency Compliance: Cisco EnergyWise intelligent power management framework full support; deep-sleep low-power idle mode activation during off-hours non-business periods to reduce corporate facility electrical energy consumption

Core Telephony, UC & Global Enterprise Feature Set

The CP-9951-K9 runs a unified dual-protocol single-image firmware file that natively supports two separate enterprise UC deployment architectures without requiring separate firmware reflashing operations to switch between platforms:

1. SCCP Skinny Client Control Protocol: Native registration to on-premises Cisco Unified Communications Manager (CUCM) and CUCM Business Edition versions 7.1.5 and later
2. MPP Multiplatform SIP Firmware: Cloud UCaaS hosted calling deployments including BroadWorks third-party service provider PBX platforms (SIP support officially released July 2011)

All core device configuration parameters, VLAN security profiles, LDAP corporate directory server addresses, XML enterprise application definitions, and unified firmware image versions are automatically retrieved via zero-touch TFTP auto-provisioning workflows upon every power-on boot cycle or charging dock connection, eliminating manual local configuration setup by end users.

1. Multi-Line Multi-Call VoIP Voice Call Handling Supports five independent directory number (DN) line identity registrations, multi-call-per-line functionality enabling multiple concurrent active/incoming voice calls per line plus native call waiting alerting for new inbound calls during existing active conversations. Supported core enterprise call handling functions: supervised consultative call transfer, blind unsupervised transfer, three-way ad-hoc audio or optional USB VGA video conference calling, call hold/resume, one-touch global microphone mute, call park, directed/group call pickup, all-condition call forwarding (unconditional / busy line / no-answer timeout), Do Not Disturb (DND) mode, Caller ID name/number full-color display for all inbound ringing voice calls, automatic last-number redial, pre-dial number editing before call initiation, intercom auto-answer for internal cross-department peer communications across multi-region global campus enterprise networks. Supplementary advanced enterprise telephony features include MLPP multilevel precedence and preemption priority call routing, barge/cbarge intrusive call monitoring, meet-me conference bridges, malicious caller ID logging, customizable touchscreen soft-key speed-dial shortcut layout editor configurable by end users.
2. Unified Cloud & Local Directory & Call Log Productivity Features Dual-source contact directory architecture combining two synchronized data repositories:

• Network LDAPv3 global corporate employee directory servers with real-time multi-language wildcard search functionality via the 5-inch touchscreen interface;
• Local persistent flash memory storage for personal address book entries, custom speed dial shortcuts, and stored call history log archives; Three distinct call log categories persistently stored locally within device flash memory: all dialed outgoing audio/video calls, all fully received answered incoming calls, all missed/unanswered ringing inbound calls. All log entries store full Caller ID metadata, precise synchronized cross-campus call timestamps, and total call duration data, with one-touch callback capability for every logged entry. Local personal address book storage supports custom user speed dial conference bridge access numbers and internal cross-region extension contacts, Bluetooth-synced mobile device contact list synchronization (via paired smartphone PBAP profile), and reverse number lookup for unknown inbound caller IDs.

1. Voicemail Message Waiting Indicator (MWI) Integration Native SCCP/SIP MWI notification synchronization with Cisco Unity / Unity Connection voicemail servers or third-party hosted voice mail platforms for global multi-region campus enterprise deployments; persistent visual MWI alert banners displayed prominently on the 5-inch touchscreen dashboard, plus steady illuminated amber handset LED strip notification when unread voicemail messages exist. Dedicated Messages menu shortcut provides instant portal access to voicemail message playback, message deletion and personalized voicemail greeting configuration.
2. Exclusive Flagship 9900 Series Core Differentiator Features vs Mid-Tier 8900 Models

• 5 independent directory number line keys (8900 Series limited to maximum 4 lines) for high-volume multi-hunt-group reception workloads
• Dual built-in USB Type-A ports (front quick-access + rear permanent mounting) for simultaneous USB video camera + USB headset / USB BLF expansion key peripheral operation (8900 Series zero or single rear USB port only)
• IEEE 802.3at Class 4 high-power PoE support (8900 Series max Class 2 PoE power budget), fully powering dual USB peripherals, Bluetooth radio, and USB video camera without auxiliary AC power adapters
• Hardware support for up to 3 separate Cisco Unified IP Color Key Expansion Modules (8900 Series limited to fewer expansion units), enabling dozens of programmable BLF presence monitoring, speed dial, and department hunt-group shortcut keys for busy reception front desk deploymentsbaynetwork...
• Optional detachable external USB VGA video camera peripheral accessory (8941 / 8961 non-video models contain zero video hardware; 8945 video model has fixed integrated non-detachable camera module)

1. User-Customizable Local Device Settings Multiple pre-built user operation profiles enabling instant one-touch switching of ringtone sets, ring volume alert levels, notification tone schemes, LCD backlight timeout durations, and audio volume presets optimized for different global hybrid-work workplace environments (quiet private clinical examination offices, noisy open-plan manufacturing production shop floors, medium-volume retail sales floors). End users can adjust display contrast, font size, screen wallpaper backgrounds, keypad lock PIN security codes, LDAP directory search filter preferences, Bluetooth device pairing and unpairing management, Wi-Fi wireless network SSID connection profile configuration, USB peripheral power management, external auxiliary audio I/O gain adjustment, USB video camera tilt and privacy shutter control settings, and local audio DSP noise cancellation strength adjustment directly via the on-device touchscreen menu system without CUCM/PBX administrator privileges. Full accessibility configuration menu including voice feedback navigation, adjustable audio pitch, TTY/TDD teletype support, and HAC handset audio tuning for hearing-impaired global users.
2. XML Extensible Markup Language Enterprise Application Support The 5-inch capacitive touchscreen renders custom XML enterprise web applications hosted on corporate internal global TFTP/HTTP/HTTPS servers, enabling global campus mobile staff to access real-time business data directly on their wired desk phone without a separate PC or tablet device. Supported XML global enterprise use cases: corporate cross-region patient room / production line status dashboards, building facility emergency contact lists for worldwide campus locations, internal company multi-language cross-border announcement feeds, multi-location conference bridge access code directories, healthcare facility patient care team cross-region contact lists, campus maintenance global work order dashboards and real-time manufacturing multi-site production line status dashboards. Cisco Compatible Extensions (CCX) compliance ensures standardized XML application interoperability across Cisco global enterprise unified communications infrastructure.

Remote Device Management & Centralized Global Administration Tools

1. Zero-Touch Centralized TFTP Auto-Provisioning & Unattended Unified Single-Image PhoneOS Firmware Upgrades Fully automated remote bulk device configuration deployment and unified single-image firmware upgrade management via standard TFTP/HTTP/HTTPS server infrastructure integrated with CUCM, Webex Calling and BroadWorks global platform deployments. The CP-9951-K9 wired desk IP phone automatically retrieves its unique device configuration file, LAN security VLAN profiles, LDAP directory multi-region server addresses, XML application definitions and latest unified PhoneOS firmware version upon every power-on boot cycle without manual on-site global IT intervention. One single universal firmware load supports all two deployment modes (CUCM SCCP / BroadWorks SIP) without separate firmware reflashing required to switch platforms, a core architectural distinction separating the 9951 flagship model from legacy multi-firmware wireless handset models.
2. Centralized Enterprise Global Device Real-Time Monitoring & Call Session Audit Logging Full device real-time status tracking available within the CUCM administrative management console or third-party BroadWorks SIP PBX global management dashboards, including wired desk phone online/offline registration state, active line audio/video call status, LAN switch access point association information, PoE power draw metric, installed unified PhoneOS firmware version number, attached downstream PC passthrough connection status, dual USB peripheral device detection status, optional USB video camera active/inactive status, and historical cross-campus audio/video conference call session audit logging for complete enterprise voice communications traceability and global IT troubleshooting. Built-in on-device network diagnostic tools include LAN wired signal strength measurement and ping utility testing to validate global campus LAN connectivity and CUCM/SIP PBX global server reachability for on-site regional IT troubleshooting teams. An embedded local HTTPS web server on the wired desk phone enables remote off-site cross-region access to device status statistics and read-only configuration data for centralized global monitoring without physical on-site access to the desk phone unit.
3. Mass Global Fleet Configuration & Troubleshooting Utilities Centralized bulk configuration export/import functionality for consistent standardized phone setting deployment across hundreds or thousands of global enterprise campus wired desk IP phone fleets distributed across EMEA, APAC, Latin America and North America; remote wired packet capture diagnostic tool for capturing local LAN voice/media and signaling packets to diagnose audio quality and cross-campus registration connectivity issues; problem reporting tool (PRT) for generating standardized device diagnostic log bundles to submit to Cisco global TAC technical support for hardware/firmware fault resolution.

Environmental & Global Regulatory Compliance Certifications

• Electromagnetic Interference Compliance: FCC Part 15 Class B, CE EMC Directive 2014/53/EU, AS/NZS CISPR22 Class B, ICES-003 Class B, VCCI Class B, KN22 Class B, CNS13438 Class B (full global multi-region EMC certification suite)
• Electrical Safety Certifications: UL / C-UL 60950 Second Edition, UL / C-UL 62368-1, EN 60950 Second Edition (including A11/A12 amendments), EN 62368, IEC 60950 Second Edition (including A11/A12 amendments), CSA C22.2 No. 60950 Second Edition, CSA C22.2 No. 62368-1, AS/NZS 60950, GB4943 China national electrical safety standard (universal worldwide safety certification)
• Telecommunications Regulatory Approvals: FCC Part 68 telephony terminal device certification, TIA 810A HAC hearing-aid compatibility standard, TIA 920 wideband HD audio compliance
• Wireless Radio Compliance (Bluetooth 2.1 LE): FCC Part 15 Subpart C, CE RED Directive 2014/53/EU, IC RSS-210, Japan MIC, Australia RCM, New Zealand RSM
• Material Compliance: Lead-free construction materials, RoHS hazardous substance compliance for commercial enterprise worldwide deployments
• Lifecycle Status: End-of-Sale (EoS) flagship 9900 Series executive desk phone model; Cisco no longer produces new manufacturing stock, limited remaining refurbished / surplus inventory availability only. Cisco continues to release periodic critical security vulnerability and severe bug-fix maintenance unified PhoneOS firmware updates for active support lifecycle customers.
• Standard Warranty: One-year limited Cisco hardware warranty covering manufacturing defects in the wired desk phone chassis, integrated 5-inch color touch LCD display panel, internal audio DSP components, Gigabit LAN Ethernet switch hardware, embedded Bluetooth wireless radio module, dual built-in USB Type-A port peripheral controller hardware, and all internal electronic components, valid for commercial enterprise worldwide global deployments across all international regions.

Key Specification Bullet Points

• Model Number: Cisco CP-9951-K9 (Cisco Unified IP Phone 9951 Standard Handset Charcoal Grey Chassis)
• Arctic White Chassis Alternative SKU: CP-9951-W-K9; Slimline Low-Profile Handset Variant SKU: CP-9951-L-K9; Optional USB Video Camera Accessory SKU: CP-9951-CAM-K9
• Legacy EoS End-of-Sale Platform: Cisco 9900 Series Unified IP Premium Executive Media Desk Phones (Discontinued Production)
• Device Type: Global Enterprise Flagship Premium Executive Wired PoE Desktop VoIP Voice & Optional VGA Video Desk IP Phone (Fixed Chassis, Dual Built-In USB Type-A Ports, Embedded Bluetooth 2.1 LE Wireless Radio Hardware, Supports Up To 3 External Color BLF Key Expansion Modules)
• Supported Telephony Firmware Architecture: Single Unified Cross-Platform PhoneOS Firmware Image (Two Deployment Modes Natively Supported):
  1. SCCP (Skinny Client Control Protocol): Native CUCM On-Premises Global Multi-Region Campus Deployment
  2. MPP Multiplatform SIP: BroadWorks Hosted Third-Party PBX Cloud UCaaS
• Display Hardware: 5-inch Backlit Color VGA Capacitive Touchless TFT LCD, Native 640 × 480 Resolution, Automatic Ambient Light Backlight Dimming, Multi-Language Right-to-Left Global Unicode UI Rendering, XML Enterprise Application Full-Color Rendering Support
• Unique Exclusive Flagship Hardware Differentiators vs 8900 Series Mid-Tier Models: 5 Independent Directory Number Line Keys (8900 Series Max 4 Lines); Dual Built-In Front + Rear Full-Size USB Type-A Ports For Simultaneous USB Camera + USB Headset / BLF Expansion Module Peripheral Connectivity; IEEE 802.3at Class 4 High-Power Dual PoE Support (8900 Series Limited Class 2 PoE); Hardware Compatibility For Up To 3 Separate Cisco Color Key BLF Expansion Modules; Optional Detachable External USB VGA Video Camera Peripheral Accessory (8941 / 8961 Non-Video Models Zero Video Hardware, 8945 Video Model Fixed Non-Detachable Integrated Camera)
• Line Support: Five Independent Directory Number (DN) Logical Base Line Identity Registrations (5-Line Multi-Line Enterprise Voice Support), Tri-Color LED Per-Line Status Indicator Lights
• Dedicated Fixed-Function Hard Key Layout (Front Chassis Bottom Panel): Hold Toggle Key, Transfer Call Key, Redial Last Number Key, Three-Way Conference Call Key, Vertical Volume Up/Down Rocker Toggle Key; Four Dynamic Context-Sensitive On-Screen Soft Keys + Horizontal Scroll Navigation Toggle Bar
• Audio Subsystem: Wideband G.722 HD Voice Support, Smart Audio Multi-Band Background Noise Cancellation DSP, Full-Duplex Digital Echo-Canceling Internal Desktop Loudspeakerphone, HAC Hearing-Aid Compatible Handset Receiver, TTY/TDD Teletype Accessibility Support, RJ-9 Modular Wired Headset Jack (EHS Electronic Hookswitch Remote Call Answer/End Control Compatible) + Integrated Built-In Bluetooth 2.1 LE Wireless Headset Pairing Support + Dual Built-In USB Type-A Ports For USB Enterprise Headset Peripherals
• Wired LAN Connectivity Hardware: Dual Independent 10/100/1000BASE-T Gigabit Ethernet RJ-45 Integrated Switch Ports (Primary PoE Uplink Port + Secondary Downstream PC Passthrough Port), IEEE 802.3af Class 1 / IEEE 802.3at Class 4 Dual PoE Power Input Support
• Power Supply Architecture: Dual Primary IEEE 802.3af Class 1 / IEEE 802.3at Class 4 PoE Power Over Ethernet (48 VDC Nominal Input); Optional Separate External 48V DC Wall-Mount AC Power Cube Adapter (Sold Separately As Accessory SKU CP-PWR-CUBE-3=); Universal Regional AC Wall Power Clip Accessories Sold Separately For Worldwide Mains Voltage Compliance
• Power Efficiency: Cisco EnergyWise Energy Management Framework, Automatic Low-Power Deep-Sleep Idle Mode Activation During Off-Hours Non-Business Periods, Energy Star Certified Low-Power Idle Mode
• Physical Mounting Options: Dual-Position Adjustable Desktop Foot Stand (Two Tilt Viewing Angles); Optional Separate VESA Wall-Mount Conversion Bracket Accessory (Sold Separately); No Portable Handheld / Mobile Form Factor (Fixed Wired Desktop Chassis Only)
• Physical Security: Integrated Rear Chassis Lock Slot For Optional Anti-Theft Desk Mount Locking Hardware
• Peripheral Interfaces: RJ-9 Four-Conductor Modular Wired Headset Jack, Removable Standard Handset Coiled Cord Connection Port, Dual RJ-45 10/100/1000 Gigabit Ethernet Integrated Switch Ports, DC Power Input Barrel Jack (For Optional External AC Power Cube Adapter), Dual Built-In Front + Rear Full-Size USB Type-A Peripheral Ports For USB Video Camera / USB Headset / USB BLF Key Expansion Module Connectivity, Integrated Bluetooth 2.1 LE Wireless Radio Module
• Supported QoS & Wired LAN Network Standards: IPv4 Only, Cisco Discovery Protocol (CDP), LLDP-MED Endpoint Discovery Protocol, 802.1Q Tagged Voice VLAN Segmentation, IEEE 802.1p Layer 2 CoS Traffic Prioritization, DSCP Differentiated Services Marking For Voice/Media Packets, QBSS Load Balancing, STUN / TURN / ICE NAT Traversal For Remote Cross-Border Worker Home Office Deployments, SNTP Synchronized Global Network Time Protocol, TFTP/HTTP/HTTPS Zero-Touch Auto-Provisioning & Bulk Global Unified PhoneOS Firmware Upgrades
• Enterprise Global Security Features: TLS Transport Layer Encryption For SCCP/SIP Call Signaling, SRTP AES Encrypted Wideband/Narrowband Voice & H.264 VGA Video Media Streams, Secure Boot Firmware Integrity Validation, SHA-256 Cryptographic Certificate Validation, SCEP Automatic Digital Certificate Enrollment For Enterprise LAN Wireless Security, Encrypted Local Stored Credentials & Configuration Data, Dual-Tier Admin/User PIN Access Restrictions, Password-Locked Factory Reset Function
• Core Unified Communications Global Voice & Optional Video Call Features: Five Independent DN Logical Base Line Identities, Multi-Call-Per-Line with Call Waiting, Blind/Consultative Call Transfer, Three-Way Wideband Audio / Optional External USB VGA 640×480 Video Conference Bridge, Hold/Resume, One-Touch Global Mute, Call Park, Directed/Group Call Pickup, All-Condition Call Forward (Unconditional/Busy/No Answer), DND Do Not Disturb Mode, Caller ID Name/Number Full-Color Global Display, Auto Redial, Pre-Dial Number Editing, Intercom Auto-Answer, Custom Touchscreen Speed-Dial Shortcut Layout Editor, MLPP Multilevel Precedence & Preemption, Barge/CBarge Intrusive Call, Meet-Me Conference Bridges, Malicious Caller ID Logging, Multiple Customizable User Ringtone/Alert Profiles, Keypad Lock PIN Security, XML Custom Enterprise Global Business Application Rendering (CCX Compliant)
• Exclusive Global Campus Office Desktop Core Flagship Premium Media Feature: Fixed Wired PoE Desktop Chassis Design, 5 Independent Multi-Line Enterprise Voice Directory Number Support, Dual Gigabit Ethernet Integrated Switch For Shared PC Desktop Passthrough LAN Connectivity, Embedded On-Chassis Bluetooth 2.1 LE Wireless Radio Hardware For Bluetooth Headset & Mobile Smartphone Contact Synchronization Support, Dual Built-In Front + Rear USB Type-A Peripheral Ports For USB Headsets, USB VGA Video Camera And External Color BLF Key Expansion Modules, Hardware Compatibility For Up To 3 Separate Cisco Unified IP Color Key Expansion Modules, Optional Detachable External USB VGA Video Camera Peripheral Accessory For Native Point-To-Point Desktop Video Conference Calling, Unified Single Cross-Platform PhoneOS Firmware Eliminating Separate CUCM/SIP Firmware Reflashing Administrative Overhead, Full ADA Accessibility Compliance For Hearing-Impaired & Disabled Office End Users
• Productivity & Directory Global Features: Network LDAPv3 Corporate Multi-Region Employee Directory Real-Time Multi-Language Search, Local Persistent Flash Memory Call Log Storage (Dialed Outgoing / Received Answered / Missed Incoming Global Campus Voice Conference Calls), Bluetooth-Synced Mobile Contact List Storage, Unified Webex Cloud-Synced Cross-Device Contact & Call History Logs, One-Touch Voicemail MWI Access Portal
• Centralized Global Management & Admin Tools: TFTP Zero-Touch Auto-Provisioning & Remote Bulk Global Unified PhoneOS Firmware Upgrades, CUCM / Webex Control Hub / BroadWorks SIP PBX Central Real-Time Device Status Monitoring & Call Session Syslog Global Audit Logging, On-Board Wired LAN Signal Strength & LAN Ping Diagnostic Utility, Embedded Local HTTPS Web Administration Server, Remote Wired Packet Capture Diagnostic Tool, PRT Problem Reporting Log Generation Utility
• Target Global Deployment Scenarios: Multinational enterprise corporate office senior executives, administrative secretaries, department team supervisors, small & medium business (SMB) general office staff, branch office shared front desk reception workstations, auxiliary call center agent secondary station deployments across EMEA, APAC, Latin America and North America, distributed multi-region campus wired desk IP phone fleets, organizations running CUCM on-premises unified communications infrastructure, BroadWorks hosted SIP PBX global cloud platforms, wired LAN infrastructures standardized on IEEE 802.3af / 802.3at PoE enterprise access switches, global IT teams prioritizing fixed wired desktop multi-line VoIP desk phones with dual built-in USB peripheral port support for USB headsets and USB BLF presence monitoring expansion key modules, optional detachable external USB VGA video camera peripheral accessory for native point-to-point desktop video conference calling functionality, unified cross-platform single-image PhoneOS firmware eliminating separate CUCM/cloud SIP firmware reflashing operations, full ADA accessibility compliance for regulated public sector and healthcare enterprise deployments, robust enterprise TLS/AES encrypted audio/video media communications security for worldwide cross-border corporate campus office desk phone fleets operating in high-traffic executive front desk workplace environments requiring flagship multi-line media collaboration endpoints with expandable BLF key module support.
• Lifecycle Status: End-of-Sale (EoS) Legacy 9900 Series Unified IP Premium Executive Media Desk Phone Hardware, No New Production Manufacturing Stock Available, Limited Refurbished / Surplus Inventory Only; Actively Supported Critical Security & Bug-Fix Maintenance Unified PhoneOS Firmware Release Schedule Maintained Per Cisco Global Support Lifecycle Policy
• Standard Warranty: One-Year Limited Cisco Worldwide Commercial Enterprise Hardware Warranty Valid Across All Global International Regions

Model Quick Reference

The Cisco CP-9951-K9 (Cisco Unified IP Phone 9951) is Cisco’s flagship premium executive fixed wired desktop multi-line VoIP media desk IP phone belonging to the discontinued 9900 Series unified IP endpoint product line, designed exclusively for high-end corporate executive office desktop deployments and busy multi-hunt-group front desk reception stations requiring expandable BLF presence monitoring key module support, five independent multi-line directory number enterprise voice support, dual-port integrated Gigabit Ethernet switch for shared desktop PC LAN passthrough connectivity, embedded built-in Bluetooth 2.1 LE wireless radio hardware for native Bluetooth headset and mobile smartphone contact synchronization functionality, dual built-in front and rear USB Type-A peripheral port support for USB enterprise headsets and optional detachable external USB VGA video camera peripherals for native point-to-point desktop video conference calling, alongside unified dual-protocol SCCP/SIP single-image firmware architecture compatible with both on-premises CUCM unified communications manager and third-party BroadWorks hosted SIP PBX cloud platforms.

Defining Hardware & Feature Differences Between CP-9951-K9 Flagship 9900 Series Model and Lower-Tier CP-8941 / CP-8945 / CP-8961 8900 Series Mid-Tier Desk Phones

1. Five independent directory number line keys (all 8900 Series models limited to maximum four line keys) to support high-volume multi-hunt-group reception workloads and executive multi-line enterprise voice deployments
2. Dual built-in front + rear full-size USB Type-A peripheral ports (all 8900 Series models feature zero or only a single rear-mounted USB port with no front quick-access USB port available) enabling simultaneous connection of USB video camera peripherals and USB enterprise headsets or external USB BLF presence monitoring key expansion modules
3. IEEE 802.3at Class 4 high-power PoE power input support (all 8900 Series models limited to lower Class 2 PoE power budget) to fully power dual USB peripheral devices, embedded Bluetooth wireless radio hardware, and external USB video camera peripherals without requiring separate auxiliary AC power cube adapters
4. Hardware compatibility for up to three separate Cisco Unified IP Color Key Expansion Modules (all 8900 Series models limited to support for fewer expansion key modules), allowing dozens of programmable BLF presence monitoring, speed dial shortcut, and department hunt-group access keys for high-traffic shared front desk reception workstation deployments
5. Optional detachable external USB VGA video camera peripheral accessory (CP-8941 and CP-8961 non-video 8900 Series models contain zero integrated video hardware of any kind; CP-8945 video-equipped 8900 Series model features a fixed permanently integrated non-detachable front video camera module with no removable peripheral camera accessory option)
6. Identical core enterprise voice, audio, network, unified communications feature set hardware specifications shared between CP-9951-K9 flagship 9900 Series model and all mid-tier 8900 Series desk phone variants: 5-inch VGA backlit color touchscreen LCD display, four-line multi-call voice support (9951 upgraded to five lines), dual Gigabit LAN passthrough switch ports, integrated Bluetooth 2.1 LE wireless radio hardware, HD wideband G.722 audio DSP engine, IEEE 802.3af/802.3at dual PoE power input compatibility, unified SCCP/SIP single-image PhoneOS firmware architecture, and complete ADA accessibility compliance. All primary voice, audio, network and unified communications feature functionality is fully matched between the 9951 flagship model and 8900 Series mid-tier models; the only permanent differentiators center on maximum directory number line count, quantity and accessibility of built-in USB peripheral ports, PoE power budget classification, maximum supported BLF key expansion module quantity, and availability of detachable external USB video camera peripheral accessory support.

Unlike Cisco’s entry-level non-video wired desk IP phones (7800 Series, CP-8811-K9) and mid-tier mainstream office video / non-video desk IP phones (CP-8941 / CP-8945 / CP-8961 8900 Series), the CP-9951-K9 flagship premium media collaboration model fills the high-end enterprise executive and busy multi-hunt-group front desk market segment that requires five-line multi-line enterprise voice support, dual built-in USB peripheral port connectivity for USB headsets and USB BLF presence monitoring expansion key modules, optional detachable external USB VGA video camera peripheral accessory for native point-to-point desktop video conference calling functionality, expandable up to three separate Color Key BLF expansion module hardware compatibility, high-power Class 4 dual PoE power input support, embedded Bluetooth wireless headset and mobile smartphone contact synchronization radio hardware, alongside full enterprise unified communications SCCP/SIP dual-protocol compatibility for mixed CUCM on-premises and hosted SIP PBX hybrid UC environments worldwide.