COMfortel® D-400

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 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, 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

Everything you need to know about our products comes now. Scroll down for more information.

Comfort Features

  • 6 SIP identities/accounts
  • 4 simultaneous connections
  • Reliability and constant availability thanks to fallback identities1
  • Caller ID – display phone numbers and names from the local and central telephone book from the communication server / cloud PBX2
  • Call waiting
  • Reject calls
  • Do-not-disturb (DND) locally via the telephone or centrally via the communication server / cloud PBX2
  • Pickup – fetch a call with pre-check
  • Call parking / open inquiry2
  • Call forwarding/transfer of calls with and without announcement
  • Call forwarding via telephone or centrally via the communication server / cloud PBX2
  • Call on hold
  • Local splitting via telephone or centrally via the communication server / cloud PBX2
  • Local 3-party conference calls via telephone or centrally via the communication server / cloud PBX2
  • Differentiation of call types through distinctive ringtones3
  • Upload and administration of custom ringtones via the web interface4
  • Call back on busy – intuitive setup of an automatic call back3
  • Convenient management of the most important phone functions via Action URL such as5
  • Support of IP cameras3
  • Dial plan for complex dialling rules
  • Telephone book, 2,000 entries locally in the telephone
  • 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)2
  • 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 muting2
  • 20 self-labelling and freely programmable function keys with multi-coloured status signalling
  • Configuration of custom images as icons for function keys via the web interface or via provisioning6
  • Busy Lamp Field (BLF) function for displaying the call and busy status of extensions2
  • Native OpenVPN support for telephony across all your sites
  • Setting your own picture as background on the phone's home screen via provisioning4
  • 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 mountable7
  • 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 functions5

Audio Features

  • High voice quality through echo cancellation
  • Codecs: G.722 (wideband), G.711 A-law/µ-Law, G.726, G.729, iLBC
  • 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
  • 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 From V1.4A or higher
2 Depending on the central communication server / cloud PBX
3 From V1.6A or higher
4 As of V1.10A or higher
5 As of V1.4A or higher
6 From V1.10A or higher
7 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


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

ICT System

COMmander® 6000RX

Fully modular ISDN/VoIP communication server for 19" racks; up to 38 exchange line channels and 112 subscribers, 15 module slots

COMtrexx® VM

Hardware independent soft PBX solution with up to 250 users and up to 250 parallel calls per system

COMmander® 6000R

Fully modular ISDN/VoIP communication server for 19" racks; up to 38 exchange line channels and 112 subscribers, 5 module slots

COMpact 4000

Semi-modular, wall-mounted compact ICT system (VoIP, ISDN, POTS); 10 channels to service provider and 16 subscribers max., 2 expansion slots

COMtrexx® Business

Large ICT all-rounder with traditional interfaces and new COMtrexx firmware and up to 150 users

COMtrexx® Advanced

Ultimate performance COMtrexx Appliance 


COMfortel® PoE-1000

PoE feed-in adapter for supplying power to PoE-enabled IP end devices via the Gigabit Ethernet connection

COMfortel H-500

Professional wireless headset for comfortable freedom of movement with highest sound quality

COMfortel® H-200

Minimalist design with professional sound

COMfortel® D-Stick EZC-5200BS

Bluetooth extension for the COMfortel® D-400

COMfortel® D-Mount

Wallmount for phones of the COMfortel® D series

COMfortel® D-XT20i

Scalable extension – Maximum variety in business communications

COMfortel® DECT Headset

Professional cordless headset for connecting to the COMfortel® system telephones with EHS support

More security for your device

Benefit from comprehensive protection. We offer you various possibilities to take advantage of our guarantees. So you are always on the safe side, no matter what your needs are. As a standard, you receive a 24-month warranty from us, through a specialist dealer even 36 months. With an additional fee-based warranty extension, you can extend your warranty to a maximum of 60 months. Please note that the warranty extension by a further 24 months can only be redeemed within the first 6 months after purchase of this product described here.

Extend now

Best Practice

Telecommunication solutions for healthcare – Nursing and residential homes

FONtevo offers greater vitality for nursing and residential homes

Employees: 17

"Some of our residents are still very sprightly but others are dependent on support for every movement. Consequently, simple communication systems that the patient or the nurse, who is often under time pressure, can control intuitively are in demand. Our nurse call system, which is connected to an …

Caren P. Managing Director

Read more

Telecommunication solutions for wholesale and retail – Car dealership

„Putting car dealerships into the fast lane“

Read more

Top Sellers

Sales Configurator (SC)

- the easy way to the right system

Customer requirements for communication solutions are constantly increasing and with them the complexity and scalability of ITC systems. Project planning therefore takes up more and more time. Here, the free Sales Configurator offers a simple and fast solution. It gives you the opportunity to efficiently plan communication solutions and create project planning proposals.

Sales Configurator (SC)