The Cisco 1 and 2-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.