A variety of headsets are available as accessories for both Cisco VoIP phones and Siemens ISDN system phones. These can be corded or cordless (Bluetooth/DECT), with different holding devices and monaural or binaural (i.e. one or two earpieces). There are a variety of manufacturers and possibly necessary adapters. Headsets are special accessories and must be purchased and financed by the user. The ZIH-NK must be informed of the planned use so that any necessary adjustments can be made to the settings of the TC system.
Cisco telephones already have an integrated headset jack. Many headsets already come with a corresponding connector/adapter.
The ElectronicHookSwitch function (EHS - i.e. call acceptance on the headset without pressing a button on the phone) on cordless headsets works on the CP-8851 phones with suitable USB headsets. A special EHS cable is required for the CP-7841 phones.
Please note that USB connection to a CP-8851 phone with keymodule is not possible with some headsets.
The CP-8851 phone has a Bluetooth interface and can be paired with Bluetooth headsets.
Cisco has also published a website for the VoIP softphone client Cisco Jabber, where suitable headsets for PC and MAC are listed. The compatibility refers in particular to the additional functions on the headset, such as answering and ending calls, muting or volume control. Pure audio compatibility should be guaranteed with any headset that is supported by the operating system. Compatible hands-free devices and handsets are also listed.
Siemens OptiPoint 500 Basic and Standard require an additional adapter (acoustic adapter) to connect a headset. OptiPoint 500 Advance are already equipped with a headset jack. The Unify Openstage 30T also have a headset jack.
Suitable headsets from Jabra can be displayed in the headset compatibility overview. Select "Cisco" as manufacturer and e.g. "Unified IP Phone 7841" as model.
You can find suitable headsets from Poly (Plantronics) in the compatibility guide on the manufacturer's website. Select "Cisco" as the manufacturer and "7841 (Cisco)" as the device, for example.
There is also a compatibility overview for EPOS headsets, where you can find headsets suitable for your phone and any necessary adapters.
Logitech unfortunately does not offer a compatibility matrix, so it is not that easy to find suitable headsets. Logitech focuses on Bluetooth and USB headsets, but whether these are also compatible for the Cisco CP-8851 VoIP phone has not been tested yet.
Cisco offers headsets specially adapted to their own VoIP telephones, which integrate optimally with special functions. Here the firmware can be kept up-to-date centrally via the telephony system. Information is available at https://www.cisco.com/c/en/us/products/collaboration-endpoints/headsets/index.html.
Pearl.de offers a simple and inexpensive headset ("Callstel Profi-Telefon-Headset PE-4603-909 inkl. Connectorbox für Festnetztelefone"), which is suitable for 90% of all desk phones on the market. This headset is either connected to the headset jack of the phone or simply looped in between the handset and the phone. The included connector box adapts the headset to the respective phones and amplifies the signal (2xAA battery or separately purchased 6V power supply). The headset doesn't offer upscale features like noise cancellation and volume limiting, but for the price of about 50 EUR, it offers acceptable listening and speech quality.
The headset has been tested with the following ISDN and VoIP phones operated at TUD: Cisco CP-7841/6945 and Cisco CP-8851/8961, Siemens OptiPoint500, Unify OpenStage 30T, Euroset/Gigaset 5020, Gigaset DA610.
Please note that this is a low-price product and therefore no "top performance" can be expected in terms of quality.