The Cisco ® IP Communications voice/fax network modules provide enterprises, managed service providers, and service providers the ability to directly connect the public switched telephone network (PSTN) and traditional telephony equipment (private branch exchange [PBX], key system, analog telephones, fax machines, etc.) to Cisco 2800, 2900, 3800 and 3900 Series Unified Communications routers. This set of Cisco IP Communications voice/fax network modules delivers the most versatile combination of analog and digital voice and data capabilities in a single network module. As a completely integrated component of the Cisco Unified Communications solution including Cisco Unified Communications Manager (UCM), Cisco IP phones, Cisco Unity ® unified messaging software, Cisco IP Contact Center (IPCC), and the entire line of Cisco IP Communications products, the Cisco IP Communications voice/fax network modules are a cornerstone of Cisco Unified Communications. When used in a Cisco unified communications router with Cisco UCM, Cisco Unified Survivable Remote Site Telephony (SRST), or Cisco UCM Express, the Cisco IP Communications voice/fax network module is a complete IP Communications solution for the business branch.