Cisco VIC3-4FXS/DID. Voice codecs: G.711,G.722,G.723.1,G.726,G.728,G.729,iLBC, Compatible operating systems: Cisco IOS. VoIP protocols: cRTP, Supported network protocols: FXO/FXS,DTMF

Cisco voice interface cards (VICs) support voice technologies. VICs can be installed in interface card slots on supported Cisco access routers or in 1- or 2-slot voice network modules that are installed in network module slots on supported Cisco access routers.

A Foreign Exchange Station (FXS)/Direct Inward Dialing (DID) interface connects directly to a standard telephone, fax machine, or similar device. This interface supplies ringing voltage, dial tone, and so on to the station.