* Added a little  CTI  functionality:  cFos  can  be  used  by
            applications to  establish  calls  (such  as  Windows  Phone
            Dialer),  as  long  as  CAPI  supports   the   corresponding
            "supplementary services". By now we know of  3  cards  which
            support this:

            AVM Fritzcard, supports SUSPEND/RESUME, HOLD/DISC & ECT
            HST Saphir, supports SUSPEND/RESUME, HOLD/DISC & ECT
            Teles cards, supports SUSPEND/RESUME

            To use it, initialize cFos as follows:

               ATS16=1 S17=1 S20=3 S88=x &S5="num"

            You can also use  the  "cFos  CTI  support"  TAPI  modem  to
            simplify initialization.

            x is the CTI method:

              0 = off
              1 = SUSPEND/RESUME, "num" specifies a call park ID. On ATD
                  <phonenum> cFos dials <phonenum> and parks  the  call.
                  Then you can unpark the call with the ID specified  in
                  register &S5.
              2 = HOLD/DISC, to be used with an  internal  ISDN  bus  of
                  your local phone exchange (PABX). "num" specifies  the
                  phonenumber of your local  phone.  On  ATD  <phonenum>
                  cFos establishes a call  to  your  phone  with  number
                  <num> and, when successful, dials the number specified
                  by <phonenum> and transfers the call.
              3..6 = ECT, different variants. Some switching equipment
                  supports ECT instead of HOLD/DISC. You can try these
                  variants if HOLD/DISC doesn't work.

            Hints:  Your  local  phone  exchange  may   require   slight
            modifications to the phone numbers you specify: e.g. if your
            local phone has number 11, it can be neccessary to  specifiy
            011 or *11 to tell your switch it's an internal  phone.  The
            same is true for your dialed phonenumber. For  example  with
            the current configuration of my Euracom 3.x I have to prefix
            the internal number with * and the external  number  with  0
            when I use S88 modes 2 or 3.
            In order to know what state your  calls  are  currently  in,
            watch the cFos status window instead of the  output  of  the
            Windows Phone Dialer. This is because ISDN behaves  slightly
            different than a modem connected in parallel to your phone.

            We  thank  *Tobias  Erichsen*  (www.te-systems.de)  for  his
            advice for implementing CTI support.