COMfortel® D-400 white

Office or home office – the COMfortel D-400 SIP phone is the professional choice

Intuitive user interface

High-resolution 4.3” TFT display with capacitive touch function

20 self-labelling function keys on the display incl. status signalling

HD audio quality thanks to wideband

Headset connection with EHS support

Your advantages in detail

The COMfortel D-400 is the premium product of our standard SIP telephony offering. It has a clear design that is dominated by a large touchscreen and blends in well with any modern office environment. Its high-resolution 4.3” colour display with capacitive touch function is designed for intuitive operation and is context-specific. An all-round visible casing LED ensures that everyone can see you are on the telephone, even if you make calls by using a hidden headset. Incoming calls and missed calls are also displayed conspicuously.

The expansion options of the COMfortel D-400 prove its professional versatility: whether you use the COMfortel D-400 with its 20 digitally labelled and freely programmable function keys, displayed on the screen, or upgrade to 80 keys with the COMfortel D-XT20i key extension module – it’s all done via the two USB connections. It's the ideal companion for your office or home office.

Compatible products

Features & technical data

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Comfort Features

  • 6 SIP identities/accounts
  • 4 simultaneous connections
  • Reliability and constant availability thanks to fallback identities
  • Caller ID – display phone numbers and names from the local and central telephone book from the communication server / cloud PBX1
  • Call waiting
  • Reject calls
  • Do-not-disturb (DND) locally via the telephone or centrally via the communication server / cloud PBX1
  • Pickup – fetch a call with pre-check
  • Call parking / open inquiry1
  • Call forwarding/transfer of calls with and without announcement
  • Call forwarding via telephone or centrally via the communication server / cloud PBX1
  • Call on hold
  • Local splitting via telephone or centrally via the communication server / cloud PBX1
  • Local 3-party conference calls via telephone or centrally via the communication server / cloud PBX1
  • Differentiation of call types through distinctive ringtones
  • Upload and administration of custom ringtones via the web interface
  • Call back on busy – intuitive setup of an automatic call back1
  • Convenient management of the most important phone functions via Action URL such as
  • Support of IP cameras
  • Display of messages send by e.g. alarm servers (SIP messages)2
  • Dial plan for complex dialling rules
  • Telephone book, 2,000 entries locally in the telephone
  • Synchronisation of contact and calendar data via CardDAV and CalDAV (e.g. Apple® iCloud)
  • LDAP – access via SSL to central telephone books, such as OpenLDAP or Microsoft Active Directory
  • Call lists for 100 missed, selected and accepted calls
  • XML browser for displaying central function menus and lists (such as call lists, telephone books)1
  • 5-way navigation keys
  • Function keys for call forwarding/transfer and volume setting
  • Function keys including LED signalling for access to the call list, voice mailbox, call on hold, headset operation, hands-free calling / listen-in function and microphone muting1
  • 20 self-labelling and freely programmable function keys with multi-coloured status signalling, displayed on the screen
  • Configuration of custom images as icons for function keys via the web interface or via provisioning
  • Busy Lamp Field (BLF) function for displaying the call and busy status of extensions1
  • Native OpenVPN support for telephony across all your sites
  • Setting your own picture as background on the phone's home screen via provisioning
  • Integration of function keys in own applications and processes via Lua templates
  • Casing LED for signalling active calls and incoming calls
  • Automatic backlight with adjustable brightness and switch-off time
  • Microphone muting
  • Wall mountable3
  • Telephone tilt angle: 30° or 45°

System Features on proprietary Communication Servers

  • Group login/logout
  • Caller ID – display phone numbers and names from a central telephone book
  • Do-not-disturb (DND)
  • Pickup – fetch a call
  • Call forwarding centrally via the communication server
  • Access to the central telephone book incl. display of the provided contact pictures
  • Online name search (reverse search)
  • Busy Lamp Field (BLF) for displaying the call and busy status of extensions
  • Switch central configuration profiles such as day/night switching
  • Simplified loading of the system's comfort functions
  • Display of the call flow, ideal for multi-company operation2
  • Professional intercom functions2

Audio Features

  • High voice quality through echo cancellation
  • Codecs: G.722 (wideband), G.711 A-law/µ-Law, G.726, G.729, iLBC, Opus, Speex
  • Comfort noise generation (CNG)
  • Voice activity detection (VAD)
  • Full duplex hands-free calling
  • 22 ring tones
  • Ringer, receiver, headset and hands-free volume can be set separately
  • Headset connection via RJ-45 for cordless headsets with EHS support and wired headsets


  • Password-protected web interface
  • HTTPS server/client
  • SIPS (RFC 3261) – encrypted signalling
  • SRTP (RFC 3711/RFC 4568) – encrypted transfer of voice data
  • Transport Layer Security (TLS)
  • VLAN (IEEE 802.1q)
  • VPN client integrated (IPsec, OpenVPN)


  • Configuration via web browser (HTTPS)
  • Mass installation via provisioning server: redirect server | DHCP options 66/67 | configuration update via SIP notify without restarting the telephone | transmission of settings via HTTP/HTTPS/TFTP
  • Extended functions for admins (e.g. tracing, user levels, status display)2
  • Localisation including language, time, date and sound
  • Languages: German, English, French, Greek, Polish, Spanish, Dutch, Italian

Supported Protocols

  • DHCPv4 (RFC 2131)
  • DHCPv4 Option 60 (Vendor class identifier)
  • DHCPv4 Option 66/67 (Hostname/Filename)
  • DHCPv4 Option 132/133 (VLAN-ID/VLAN-QoS)
  • DNS SRV-RR (RFC 2782)
  • STUN (RFC 3489, RFC 5389, RFC 7350)
  • HTTP/HTTPS (RFC 2616)
  • HTTPS (RFC 2818)
  • IPv4 (RFC 0791)
  • IPv6 (RFC 2460, RFC 8200)
  • IPv6 Dual Stack (RFC 4241)
  • IPv6 Dual Stack Lite (RFC 6333)
  • IPv6 SLAAC (RFC 4862)
  • BLF (RFC 4235)
  • LDAP (RFC 4511)
  • LDAP over SSL/TLS (RFC 2830)
  • NTP (RFC 958)
  • RTCP (RFC 3550, RFC 3605)
  • RTP (RFC 3550)
  • DTMF: in-band, RTP Payload (RFC 2833, 4733), SIP-INFO
  • SIP/SIPS (RFC 3261, RFC 2543)
  • SRTP (RFC 3711, RFC 4568)
  • TFTP (RFC 1350)
  • TLS (RFC 2246)
  • VLAN (IEEE 802.1q)
1 Depending on the central communication server / cloud PBX
2 Version 2.0A or higher
3 Optional



Power supply

Power over Ethernet (PoE according to IEEE 802.3af, Class 0)

Ethernet ports

2 port Ethernet switch 10/100/1000 Base-T

USB ports


System connection

Ethernet 10/100/1000 Base-T


separate interface for corded and cordless speaker/microphone sets, also with EHS support

Operating elements

keypad with vanity code, 17 dedicated function keys, 4 soft keys, 20 freely programmable function keys on the screen


TFT colour display (4.3" / 10.9 cm, 480 x 272 pixels) with capacitive touch


6, some multi-coloured


wideband audio, electret-microphone, dynamical loudspeaker, hearing aid compatible

Hook switch

magnetically switching contact


8 Ohm, Ø 52 mm





Dimensions (w x h x d)

238 mm x 160/125 mm x 145/195 mm


approx. 750 g


CE, EN 55032, EN 55024, EN 62368-1

Delivery Scope

  • Basic unit
  • Handset (receiver) with connection cable
  • Device stand
  • Ethernet connection cable RJ-45/RJ-45
  • Quick start guide

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