Ericsson T19LX User Manual page 69

Note! If you are using an application that supplies its own box for enter-
ing extra settings, then type the following command string into
that box as well:
+COS=4,1,2,1; into that box as well.
4 You are having trouble initiating data/fax calls from your com-
puter.
Check to see if your COM ports are occupied. If so, you must
temporarily disable the software applications that are using the
COM ports.
64 Data, Fax, and Internet Calls