Cisco UC520-16U-4FXO-K9 Unified Communications System

The Cisco UC520-16U-4FXO-K9 Unified Communications System is a compact Cisco CME-based telephony appliance designed for small offices that need integrated voice, messaging, and basic UC features in a single, purpose-built platform that can support ongoing business communications without a separate server. Model UC520-16U-4FXO-K9 specifies 16 user extensions (16U) and four FXO analog trunk ports (4FXO), providing PSTN connectivity and extension management from one device, while the 'K9' designation indicates the software variant of the product. The included CME Base and Unity Express (CUE) elements enable core telephony features, voicemail, and automated attendant capabilities, allowing basic messaging and call routing without additional hardware or software modules. Designed for small business environments that need to consolidate telephony, voicemail, and basic UC functionality, the UC520-16U-4FXO-K9 leverages Cisco's established CME-based workflows to deliver a cohesive, Cisco-endpoint friendly communications solution that can integrate with IP phones and support remote workers.