Cisco 3800 Series Integrated Services Routers

This 3-port FXS and 4-port FXO voice and fax expansion module provides on premises FXS signaling to connect directly to a standard telephone fax machine or similar device and supplies ring voltage and dial tone. In addition the FXO ports provide off-premises connection to the central office. FXS signaling support available includes loop-start and ground-start. There is no DID support. In addition there is no FXO power failover support on the FXO ports.