REFURBISHED GOOD Cisco UC520-16U-4FXO-K9 With adapter

✔ All-in-One Communication + Networking Platform

Functions as a voice communications system + data router + PBX — integrating analog lines (PSTN), IP-based telephony (VoIP), and Ethernet networking in one device.

Supports a complete small-office telephony setup: voicemail, auto-attendant, call routing, call transfer/hold/wait, internal extensions, and external PSTN trunk lines.

✔ Analog & VoIP Line Support

Equipped with FXO ports to connect to external PSTN lines (traditional telephone lines).

Equipped with FXS ports for connecting analog devices like legacy phones or fax machines.

Supports standard VoIP protocols (SIP, H.323, SCCP) and codecs (e.g. G.711, G.729), allowing IP phones and softphones to work alongside analog devices.

✔ Internal Extensions + PoE for IP Phones

Standard configuration supports up to 16 internal extensions/users (i.e. up to 16 phones/lines).

Built-in PoE-enabled Ethernet ports (on many units) — allows powering IP phones or PoE devices directly from the unit, reducing need for separate power adapters.

✔ Modular & Expandable Telephony Interfaces

Has a VIC (Voice Interface Card) expansion slot, enabling addition or modification of telephony interfaces (e.g. more analog ports, different trunk types) as network needs evolve.

Flexible enough to support mixed phone environments: analog phones, VoIP phones, PSTN trunk lines, fax machines — useful for small businesses transitioning to VoIP over time.

✔ Compact and Cost-Effective for Small Offices

Designed for small to medium businesses needing a unified comms + data solution in a single box.

Ideal for environments with limited equipment space or where a simple, manageable phone + data infrastructure is needed.