If you have an ISDN card with which CAPI works, you may be able to use applications that use CAPI, e.g. a fax system. At this point, AVM cards can work with CAPI, as well as some active cards. For the AVM passive cards you need to visit the www.AVM.de website. . If you need this package, it will be installed automatically via dependencies, no need to select it yourself.
