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Information Technology


General information

At HZB, telephony, which has a consistent external appearance, is essentially a complex interplay of several telephone system components of different manufacturers and technologies that are distributed to both sites (Wannsee and Adlershof) and connected to each other in different ways. The IT department is primarily responsible for the operation of these telephone systems.

Please send your questions, problems, concerns or requests by e-mail to telefonie@helmholtz-berlin.de. Alternatively, you can also use the contact form of the service desk.

How do I get a phone?

Select the telephone that is suitable for you from the overview in the section "New telephony (Voice over IP - VoIP)".

Check whether, for example, your predecessor had a telephone that you can continue to use or whether a telephone is already available in your office. In these cases, please contact your secretary to assign the phone number on the intranet.

If you need a new telephone, please contact telefonie@helmholtz-berlin.de with your request by e-mail.

Calls to external numbers

If you want to call an external number from a HZB number, you must dial an additional 0 in front. Please note the call permission of your phone number (visible in the Phone-Portal). This also applies to call forwarding. Dialing examples:

  • 030 1234567 must be dialed as 0030 1234567
  • 0151 1234567 must be dialed as 00151 1234567
  • 0049 30 1234567 must be dialed as 00049 1234567
  • +49 30 1234567 can be dialed directly like this
  • from HZB to HZB the extension number can be dialed directly, e.g. 49999

Requests and problem reports

In case of call problems, please report the following to us (e-mail to telefonie@helmholtz-berlin.de):

  • Number of the caller
  • Number of the called party
  • Date and time of the call
  • Problem description

Otherwise a problem analysis is not possible.

For general requests and problem reports regarding a phone line, please include the following:

  • Phone number
  • Location of the phone
  • Problem description

Conference call

If your workplace already has a Voice over IP phone, you can request your own conference room in your Phone-Portal.

You can also start a conference call without logging in or registering with the provider Globafy (free, instructions and further information).

New telephony (Voice over IP - VoIP)

We are modernizing and unifying HZB-wide telephony at the sites. The new telephony uses a completely different technology: Voice over IP (VoIP). The simple telephoning itself does not change. However, the new technology is more scalable, future-proof, complies with the environmental standards of the Blue Angel, unifies and simplifies the current telephone infrastructure and offers more possibilities for integration and adaptation in the HZB environment. We have already implemented these possibilities in a first step.

You can manage your phone from anywhere on the intranet using the My Phone-Portal web application.

In addition to central servers and components, new end-devices and telephones are also necessary for VoIP. These are rolled out step by step throughout HZB. Please understand that this takes a lot of time due to the quantity and individuality and that we determine the order based on defined parameters.

Instructions as well as Frequently asked questions and answers (german only) for the new VoIP phones from Polycom we have provided for you.

Desk phone

The desk phones used are "Polycom VVX 411". A manual can be found here.

Wall phone

The wall phones used are "Polycom VVX 201".


A softphone is an application on a PC or mobile device that allows you to make calls with your HZB phone number from anywhere in the world (continue to Softphone page). No physical phone is required to use the softphone.

DECT over VoIP (cordless telephony) at the Wannsee site

In the new VoIP environment we now also provide a central DECT telephony. The uniform DECT telephones from Spectralink (optional with belt clip) communicate via radio (DECT) with base stations, which are installed at selected locations on campus. The base stations in turn communicate with the rest of the infrastructure via VoIP.

With this solution (compared to e.g. the Analog Gigaset DECT telephones) some comfort functions are added, e.g. signaling of phone number and name, a central phone book and central administration options.
Further information/order by request to telefonie@helmholtz-berlin.de.

Manuals for Spectralink 7622:

Manuals for Spectralink 7722:

DECT over VoIP (cordless telephony) at the Adlershof site

"Ascom d81" are used. If you need a cordless phone, please talk to your supervisor first. Then please send an e-mail specifying the reason to telefonie@helmholtz-berlin.de.

Analog telephony

For special cases (elevators, emergency calls, intercom stations, areas without a network, etc.), analog telephone connections are still available on the VoIP system.

System/ISDN - old landline telephony

Short descriptions for the landline telephones at the Wannsee site (type Nortel / Avaya M3903 and M3904):

Short description (german)
Short description (english)

Note: Not all functions described by the manufacturer may be supported.

Mobile telephony

If you have any contractual or technical questions about your mobile phone, the ervice desk will support you.

Please deactivate the "Wifi Calling" function on your business mobile phone, otherwise calls via call forwarding will not be received reliably: Instructions for this at Vodafone (ger).