Unify’s phones typically come as HFA, TDM, or SIP variant. Each variant uses a different type of connection to the telephone system but to the user there is no visual difference between the three.

  • HFA: HiPath Feature Access. These are IP phones, using Unify’s proprietary IP communication protocol for the most feature rich phone variant available. The latest software levels also allow the phones to connect to the telephone system even if not on the same network – perfect for homeworkers and multi-site offices. In addition, HFA phones allow fail-over programming, adding resilience. HFA are the preferred variant.
  • TDM: Time Division Multiplexing. These digital phones are a long term favoured handset variant, but now HFA phones offer all the same features plus the option of fail-over and remote connection. Digital phones are full feature and best suited where traditional cabling is in place.
  • SIP: Session Initiated Protocol. SIP is a universal IP language used by most VoIP providers. SIP phones offer the same resiliency and remote access as HFA phones, with the standard SIP level feature set. Generally speaking, SIP phones are the most eco-friendly in both production and energy consumption.

If you are not sure which handset variant is best for you, or would like to visit Unify for a chance to test the phones yourself, please get in touch.

See Unify Phone; Unify’s latest web based collaboration and communications platform. Unify Phone software is compatible with any supported Deskphone device.


Unify Phone enables organizations of all sizes to embrace the benefits of cloud-based high-quality audio and video meetings, team messaging, file and screen sharing and MS Teams Integration while continuing to leverage your investment in Unify OpenScape communication technologies.

The entry level phone in the CP range; the newest range from Unify. Feature rich, superior audio quality, and reliable. The design is driven by demand for phones to be less technical and more approachable. SIP variant available.

The mid-level CP phone features a large display, programmable keys and optional key expansion modules. Interoperable with Circuit, the ground breaking web based communications platform from Unify. SIP variant available.

The CP powerhouse phone features HD voice, Circuit interoperability, Bluetooth 2.1 and 4.1 LE, and NFC for intelligent information sharing between desk phones and mobile phones. Additional key expansion modules are available. SIP variant available.

An upright phone designed for minimal desk footprint, the 35G is ideal for contact centre agents and knowledge workers. The OpenScape 35G features 3 line display, headset port and and integrated Gigabit Ethernet port as standard. HFA and SIP variant available.

The premier device for senior managers and executives, with a colour 320 x 240 LCD display, self labelling ports including shift layer, USB port, headset jack and integrated Gigabit Ethernet port as standard. HFA and SIP variant available.

The entry level display handset for the OpenStage range is full feature, with 8 programmable LED buttons and a 2 line fixed display. HFA and SIP handsets also include advanced noise rejection and echo cancellation, with the option of 10/100 or Gigabit Ethernet. Available as HFA, TDM and SIP variant.

An upgrade to the OpenStage 15 phone with additional features to include a headset port, additional feature keys and the option of additional key expansion modules; ideal for outbound call specialists. Available as TDM variant.

The large display and self labelling keys make this the ideal phone for hotdesk areas, team workers and call centre staff. Also includes a headset port, with the option of additional key expansion modules. The HFA and SIP variant have integrated 10/100 or Gigabit Ethernet ports. Available as HFA, TDM and SIP variant.

The premier handset of the OpenStage range, featuring HD voice, colour 320 x 240 LCD display, self labelling keys, high customisation and additional key expansion modules. This phone is ideal for managers, secretaries, and public impression areas. Available in HFA, TDM and SIP variant.

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