+ "\n"
+ "set LCR_TRANSFERCAPABILITY to the numerical bearer capabilty in order to alter caller's capability\n"
+ " -> use 16 for fax (3.1k audio)\n"
+ "\n"
+ "To send a fax, you need to set LCR_TRANSFERCAPABILITY environment to 16, also you need to set\n"
+ "options: \"n:t:q250\" for seamless audio transmission.\n"