The Cisco 1-port T1/E1 Multiflex Voice / WAN Interface Cards ("Multiflex VWICs") support voice, and data applications in Cisco 2600 and 3600 multiservice routers. The Multiflex VWIC combines WAN Interface Card ( WIC ) and Voice Interface Card ( VIC ) functionality to provide unparalleled flexibility, versatility and investment protection from its many uses. Customers who choose to integrate voice and data in multiple steps preserve their investment in a T1/E1 WAN interface since the Multiflex VWIC can be reused in packet voice applications. For example, the Multiflex VWIC can support data only applications as a WAN interface on the Cisco 2600 or 3600, then be re-used to integrate voice and data with the Drop and Insert multiplexer functionality and / or configured to support packetized voice ( Voice over IP [VoIP] or Voice over Frame Relay [VoFR]) when in the Digital T1/E1 Packet Voice Trunk network module.