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 existing Cisco voice gateway 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 IP Communications solution including Cisco CallManager, 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 AVVID (Architecture for Voice, Video and Integrated Data). When used in a Cisco voice gateway router with Cisco CallManager, Survivable Remote Site Telephony (SRST), or Cisco IOS Telephony Service, the Cisco IP Communications voice/fax network module is a complete IP Communications solution for the business branch.