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Cisco 8851 SIP Phone

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Cisco 8851 SIP Phone

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Cisco 8851 SIP Phone

The Cisco 8851 SIP Phone offers 5 configurable line keys for directory numbers and features like speed dial/BLF. It boasts an expansive 5-Inch color display, a USB port, dual Gigabit Ethernet ports, Wideband audio, handsfree speakerphone, headset support, and compatibility with 2 Cisco 8800 Key Expansion Modules (KEMs). It is a PoE Device; however, a PSU (sold separately) is required for non PoE setups.

Note: This is a SIP phone and is only compatible with platforms from Cisco's Multiplatform series—not Cisco Call Manager.

Product Info

The Cisco 8851 multiplatform phone firmware enables the 8800 Series to interact seamlessly with third-party call control systems. This firmware offers many features comparable to Cisco's own call control platform, though it's not completely identical. You can configure the phone's five programmable line keys to fit your needs, such as multiple directory numbers or speed dial / BLF. Additionally, it's compatible with up to two 8800 Key Expansion Modules for even more programmable funtion keys.

**Phones ordered as multiplatform phones do not work with Cisco call control**


  •     5" high resolution colour display (800x480 pixel)
  •     2x 10/100/1000 Gigabit Ethernet Switch
  •     PoE IEEE 802.3af/at Class 2 compliant (PSU available separately)
  •     Wideband audio (G.722)
  •     10 SIP accounts (SIP Registrations)
  •     5 programmable line keys
  •     Hands-free talking (speaker phone)
  •     Wall mountable (optional wall mount kit available)
  •     Headset support - Support for Wireless EHS headsets (requires EHS Adaptor)
  •     Hearing aid compatible
  •     Compatible with up to 2 x Cisco IP Phone 8800 Key Expansion Modules


  •     Codecs: G.711 (A-law andu-law), G.722.2, G.722, G.729ab, ILBC, iSAC, Opus
  •     DTMF: In-band, Out-of-band (RFC 2833) and SIP INFO


  •     MAC address (IEEE 802.3)
  •     SIP protocol support (RFC3261 and companion RFCs)
  •     IPv4 (RFC 791)
  •     DNS: A record (RFC 1706), SRV record (RFC 2782)
  •     Dynamic Host Configuration Protocol (DHCP) (RFC 2131)
  •     Simple Network Time Protocol (SNTP) (RFC 2030)
  •     NAT transversal, STUN
  •     UDP/TCP
  •     Link Layer Discovery Protocol (LLDP)
  •     Cisco Discovery Protocol (CDP)


  •     802.1x authentication
  •     Media encryption via SRTP
  •     Transport Layer Security (TLS)
  •     Encrypted configuration files
  •     Digest authentication
  •     Password Login
  •     HTTPS Secure provisioning


  •     Cisco XML services interface (XSI)

Call Control and Audio Features

  •     Busy Lamp Field
  •     Call back on busy
  •     Call blocking - anonymous and selective
  •     Call conferencing - hosted (N-party)
  •     Call conferencing - local 3-way
  •     Call forwarding - unconditional, no answer, on busy
  •     Call hold
  •     Call pickup - selective and group
  •     Call park and unpark
  •     Call transfer - attended or blind
  •     Call waiting
  •     Caller ID name and number and outbound caller ID blocking
  •     Caller ID mapping for incoming calls
  •     Configurable dial/numbering plan support with inter-digit timers - per line
  •     Configurable supplementary services soft keys
  •     Distinctive ringing based on calling and called number
  •     Do not disturb
  •     Extension mobility/hot-desking
  •     Group paging
  •     Hoteling
  •     Intercom
  •     Individual volume setting per audio path (headset/handset/speaker)
  •     Multicast paging
  •     Music on hold
  •     Outbound caller ID blocking
  •     Visual voice message indicator (VMWI)
  •     Shared/bridge line appearance
  •     Supplementary services feature activation codes


  •     Local phonebook
  •     XML/LDAP remote directory
  •     Broadsoft Directory
  •     Intelligent search
  •     Call History


  •     Configuration: Browser/Phone/Auto-provision
  •     Auto provision via TFTP/HTTP/HTTPs for mass deployment
  •     Problem Reporting Tool (PRT)

In the Box

  •     CP-8851 Phone
  •     Handset
  •     Curly Cord
  •     Desktop Stand
  •     Network Cable



If your type of device is mentioned in the text as compatible then it will without issue. All orders are double checked against the device & if we find anything that isnt 100% compatible we will tell you by phone and recommend the correct alternative.

Exactly what it says, if the goods you receive fail to please you in any way, please return them within 7 working days where we will provide a prompt and full refund and or offer you alternative products wherever possible. Goods must be returned in all original packaging, undamaged and in a resalable condition.

Yes, enter in the amount of headsets you require and your new discounted price will be shown. Discounts start at 4 units and go up from there. If you are a corporate customer who require large numbers 100+, then please telephone our corporate and contact centre team on 0161 830 6818

If you are intending to purchase several headsets (min 4+) Visit the free trial page here or telephone us on 0800 644 0424 or email and we will do the rest

Yes, next day delivery is free for purchases over £100 and is based on the working day (Mon-Fri) Orders must be received by 3pm to qualify. (except friday where the goods will be delivered the following Monday)

30 Day No quibble returns

Not happy with your product, just return it in a resaleable condition within 30 days for a full refund

Free Trials Available

Looking to purchase 4+ headsets? Why not try before you buy here

Next Working Day Delivery

Super quick & secure delivery by courier on a next working day service.