The Cisco 1-port and 2-port T1 Multi-Flex Voice/WAN Interface Cards (Multi-Flex VWICs) support voice and data applications on a variety of Cisco multiservice platforms. The platforms include the Cisco 1700, 2600, 2600XM, 2691, 3600, and 3700 multiservice routers, as well as the Cisco VG200, WS-X4604-GWY, C4224, and ICS 7750 voice gateways.
When the card is set up to use ISDN PRI signaling, ISDN data connection is not supported. The card is unable to terminate the ISDN 64 K or 56 K data connection. It supports only voice-call termination when using ISDN PRI signaling.
Also, the Multi-Flex Trunk, with or without the accompanying voice-enabling hardware, is unable to terminate a modem connection on the router in a traditional Network Access Server (NAS) dial scenario.