The Cisco Unified Communications 2-Port E&M Voice Interface Card 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, and so on) to Cisco 2800 Series and 3800 Series voice gateway routers. This set of Cisco Unified Communications voice/fax network modules delivers the most versatile combination of analog and digital voice and data capabilities in a single network module.