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snom 821 IP Phone Overview

The snom 821 is the newest IP phone from snom which packs a lot of features into a nice small footprint. With a color display and Gigabit Ethernet switch, the 821 is ideal for office workers to managers and any situation requiring high bandwidth throughput. The wideband technology used in the handset captures more than double the frequency spectrum of a standard handset, making the audio quality comparable to FM radio. On speakerphone, a Class D amplifier reliably suppresses interference noise. With the optional WIFI adapter, the snom 821 can be located anywhere in an office without having to run Ethernet cabling.

General Information

  • Weight, with footstand: approx. 900g without footstand: approx. 670g
  • Certifications: FCC Class B, CE Mark
  • Power consumption: 4-7 Watts (without USB peripherals)
  • 1 x LAN, 1 x PC: RJ45 (Ethernet)
  • Power 5V DC
  • Ethernet: 2 x IEEE 802.3/1 Gigabit Switch
  • Power over Ethernet: IEEE 802.3af, Class 2
  • Handset: RJ-4P4C connector
  • Headset: RJ-4P4C connector
  • 1 x USB Type A, 1 x Type B
  • available in black and light gray

User Interface

  • High-resolution TFT color display
  • 3.5”, 320 x 240 pixels
  • 37 keys, 9 LEDs
  • 4 freely programmable and 16 customizable function keys
  • 12 virtual keys
  • Comfortable and intuitive menu structure
  • Incoming call indication via LED
  • Caller identification on display
  • LED indication for missed calls and new messages
  • Directory (up to 1000 entries)
  • Import/export of directory
  • Speed dial
  • Local dial plan
  • Lists of missed, received, and dialed calls (250 entries each)
  • Indication of calls on hold
  • Clock with automatic daylight-saving time, call duration
  • Call blocking (deny list)
  • Blocking of anonymous calls
  • Handling of up to 12 calls simultaneously
  • Auto answer mode
  • Ringtone selection, VIP ringtones, import of individual ringtones
  • URL dialing support
  • Multiple language support
  • DND mode (do not disturb)
  • Speakerphone (full duplex)
  • Keyboard lock

Additional Functions

  • Extremely easy WLAN connection via USB
  • Hold
  • Unattended and attended transfer
  • Music on hold (if supported by PBX)
  • Call forwarding
  • 5-way conferencing (bridge on phone)
  • Call park, call pickup (if supported by PBX)
  • Call completion on busy/not available
  • Client Matter Code (CMC)
  • Call waiting/switching between calls
  • Automatic Redial
  • RTP multicast paging
  • Multiple audio device support
  • Unified Communications with snom CTI and snom OCS edition

Web Server

  • Built in HTTP/HTTPS web server
  • Remote configuration/provisioning
  • Dial from web interface or snom CTI
  • Password protection
  • Diagnostics (tracing, logging, syslog)
  • Security, Quality of Service

  • HTTPS (server/client)
  • Transport Layer Security (TLS)
  • SRTP (RFC 3711), SIPS, RTCP, VLAN (802.1pq)

Codecs, Audio

  • Wideband audio
  • G.711 a-law, µ-law
  • G.722, G.723.1, G.726, G.729AB, GSM FR, AMR
  • Comfort noise generation (CNG)
  • Voice activity detection (VAD)


  • RFC 3261 compliant
  • UDP, TCP, and TLS
  • Digest/basic authentication
  • Loose routing and strict routing
  • PRACK (RFC 3262)
  • Error information support
  • Reliability of provisional responses (RFC 3262)
  • Early media support
  • DNS SRV (RFC 3263), redundant server support
  • Offer/Answer (RFC 3264)
  • Message Waiting Indication (RFC 3842), subscription for MWI events (RFC 3265)
  • Dialog-state monitoring (RFC 4235)
  • In-band/out-of-band/SIP INFO DTMF
  • STUN client (NAT traversal)
  • NAPTR, (RFC 2915), rport (RFC 3581), REFER (RFC 3515)
  • Event list subscription support (RFC 4662)
  • Bridged line appearance (BLA)
  • Auto provisioning with PnP
  • Presence/Buddy-list feature
  • Busy lamp field support (BLF)
  • Presence publishing


  • Automatic software updates
  • Automatic settings retrieval via HTTP/HTTPS/TFTP
  • Configuration via web interface
  • Static IP, DHCP
  • NTP

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