Cisco Desk Phone 9851 DP-9851-K9 — New, Color Display Enterprise SIP Desk Phone
Warranty: Lifetime
The Cisco Desk Phone 9851 DP-9851-K9 is a brand-new, mid-tier SIP desk phone built for Cisco Unified Communications Manager (Unified CM / Call Manager) environments. It features a 3.7-inch backlit color display, six programmable line keys, USB-A and USB-C ports, a built-in two-port Gigabit Ethernet switch with PoE, and support for a Key Expansion Module, so no external power is needed. It ships with Cisco's Unified CM firmware and registers directly to a Cisco Unified Communications Manager cluster over SIP.
Key Features
- 3.7" backlit color LCD (480 x 240) display
- 6 programmable line keys, expandable up to 46 keys with one Key Expansion Module
- Full-duplex speakerphone with background noise removal on outgoing audio
- Hearing Aid Compatible (HAC) handset, ADA and Section 508 compliant
- USB-A and USB-C ports for wired headsets and accessories
- Built-in 2-port Gigabit Ethernet switch (network + PC passthrough) with PoE, no external power needed
- Enterprise security: TPM 2.0, Secure Boot, image authentication, SUDI, TLS 1.3, 802.1X supplicant
- Broad audio codec support: G.711, G.722, G.722.2, G.729ab, iLBC, iSAC, Opus
Technical Specifications
- Model: Cisco DP-9851-K9 (Desk Phone 9851, Unified CM Firmware)
- Condition: New
- Color: Carbon Black
- Display: 3.7" color LCD, 480 x 240
- Connectivity: 2x Gigabit Ethernet (RJ45, integrated switch); no Wi-Fi or Bluetooth
- USB: 1x USB-A + 1x USB-C (0.5A/5V each under PoE)
- Power: PoE IEEE 802.3at (Class 3); optional AC power adapter (sold separately)
- Call control platform: Cisco Unified Communications Manager (Unified CM / Call Manager) only
- Signaling protocol: SIP (registers to Cisco Unified CM)
- Lines: 6 programmable line keys, expandable to 46 keys with one DP-9800-KEM= expansion module (USB-A)
- Ports: 1x RJ9 handset, auxiliary port (console logging), 1x USB-A, 1x USB-C
- Dimensions/Weight: 8.9 x 8.4 x 1.9 in.; 2.13 lb (968 g)
What's in the Box
Desk phone, handset, handset cable, foot stand, Ethernet cable, and quick-start guide. AC power adapter and Key Expansion Module not included.
Frequently Asked Questions
Is the Cisco DP-9851-K9 compatible with Webex Calling, BroadWorks, or Asterisk?
No. This unit ships with Cisco's Unified CM firmware, which registers only to Cisco Unified Communications Manager (Call Manager). A separate firmware/platform load is required for Webex Calling, BroadWorks, or other SIP platforms.
Does the Cisco 9851 support Wi-Fi or Bluetooth?
No. The 9851 is a wired-only desk phone with no wireless radios. If you need Wi-Fi and Bluetooth, see the Cisco Desk Phone 9861 (DP-9861-K9).
Can the 9851 use a Key Expansion Module?
Yes. It supports one Cisco 9800 Series Key Expansion Module (DP-9800-KEM=) connected via the USB-A port, adding a 5" color touch panel with 20 programmable keys across two pages.
Does the Cisco 9851 phone require a separate power adapter?
No. It supports Power over Ethernet (802.3at, Class 3), so it can be powered directly through a PoE switch. An AC adapter is available separately if PoE isn't an option.
Is this unit new or refurbished?
This Cisco DP-9851-K9 is brand new, factory-sealed stock.
The Cisco Desk Phone 9851 DP-9851-K9 is a brand-new, mid-tier SIP desk phone built for Cisco Unified Communications Manager (Unified CM / Call Manager) environments. It features a 3.7-inch backlit color display, six programmable line keys, USB-A and USB-C ports, a built-in two-port Gigabit Ethernet switch with PoE, and support for a Key Expansion Module, so no external power is needed. It ships with Cisco's Unified CM firmware and registers directly to a Cisco Unified Communications Manager cluster over SIP.
Key Features
- 3.7" backlit color LCD (480 x 240) display
- 6 programmable line keys, expandable up to 46 keys with one Key Expansion Module
- Full-duplex speakerphone with background noise removal on outgoing audio
- Hearing Aid Compatible (HAC) handset, ADA and Section 508 compliant
- USB-A and USB-C ports for wired headsets and accessories
- Built-in 2-port Gigabit Ethernet switch (network + PC passthrough) with PoE, no external power needed
- Enterprise security: TPM 2.0, Secure Boot, image authentication, SUDI, TLS 1.3, 802.1X supplicant
- Broad audio codec support: G.711, G.722, G.722.2, G.729ab, iLBC, iSAC, Opus
Technical Specifications
- Model: Cisco DP-9851-K9 (Desk Phone 9851, Unified CM Firmware)
- Condition: New
- Color: Carbon Black
- Display: 3.7" color LCD, 480 x 240
- Connectivity: 2x Gigabit Ethernet (RJ45, integrated switch); no Wi-Fi or Bluetooth
- USB: 1x USB-A + 1x USB-C (0.5A/5V each under PoE)
- Power: PoE IEEE 802.3at (Class 3); optional AC power adapter (sold separately)
- Call control platform: Cisco Unified Communications Manager (Unified CM / Call Manager) only
- Signaling protocol: SIP (registers to Cisco Unified CM)
- Lines: 6 programmable line keys, expandable to 46 keys with one DP-9800-KEM= expansion module (USB-A)
- Ports: 1x RJ9 handset, auxiliary port (console logging), 1x USB-A, 1x USB-C
- Dimensions/Weight: 8.9 x 8.4 x 1.9 in.; 2.13 lb (968 g)
What's in the Box
Desk phone, handset, handset cable, foot stand, Ethernet cable, and quick-start guide. AC power adapter and Key Expansion Module not included.
Frequently Asked Questions
Is the Cisco DP-9851-K9 compatible with Webex Calling, BroadWorks, or Asterisk?
No. This unit ships with Cisco's Unified CM firmware, which registers only to Cisco Unified Communications Manager (Call Manager). A separate firmware/platform load is required for Webex Calling, BroadWorks, or other SIP platforms.
Does the Cisco 9851 support Wi-Fi or Bluetooth?
No. The 9851 is a wired-only desk phone with no wireless radios. If you need Wi-Fi and Bluetooth, see the Cisco Desk Phone 9861 (DP-9861-K9).
Can the 9851 use a Key Expansion Module?
Yes. It supports one Cisco 9800 Series Key Expansion Module (DP-9800-KEM=) connected via the USB-A port, adding a 5" color touch panel with 20 programmable keys across two pages.
Does the Cisco 9851 phone require a separate power adapter?
No. It supports Power over Ethernet (802.3at, Class 3), so it can be powered directly through a PoE switch. An AC adapter is available separately if PoE isn't an option.
Is this unit new or refurbished?
This Cisco DP-9851-K9 is brand new, factory-sealed stock.