The Polycom CX500 (2200-44300-025) is a desk phone built for Microsoft Lync and Skype for Business systems. Polycom no longer makes it. It is not a general SIP phone, so read the checks below first.

Check your system first

• Your office must run Microsoft Lync Server or Skype for Business. Sellers list Lync 2010 and 2013.
• The phone runs the Lync software built into it. It does not work as an open SIP phone.
• It has one Ethernet port, so a computer cannot plug into it.
• Power comes from PoE (802.3af, Class 2). An AC adapter is not in the box.
• Device-only mode means the phone needs no connection to a PC.

Where it fits

Polycom aimed the CX500 at lobbies, hallways, break rooms and small offices. The phone can hang on a wall. Polycom sold a tamper-resistant wall mount as an option.

Screen and keys

The 3.5-inch color screen shows 320 x 240 pixels. A backlight dims or sleeps to save power. Three soft keys open on-screen tasks. A two-way pad moves through lists. A 12-key dial pad, volume keys, a mute key and a status light round out the controls.

Sound

Polycom HD Voice and Acoustic Clarity give full-duplex calls with echo control and less background noise. The phone supports Microsoft RTAudio wideband, G.722.1 and G.711. The handset works with hearing aids. A handset port, RJ-9, sits on the base.

Power options and access

Polycom sold an optional 24 V AC power adapter, and a PoE injector also works. Each audio path has its own volume setting. A TTY adapter was available for users who need one. The phone body is charcoal.

Calls and contacts

The built-in Lync client shows call status, contact cards and directory data. Users can reach the corporate directory from the phone.

Polycom CX500 2200-44300-025 specifications