I am trying make a call to my brother on his tty from my laptop computer. I am using nextalk.net and it seems to be working on the computer. However I have tried many times to establish a connection and it says the phone is received at the other end but all I ever get is a buzzing sound on the headphones. Is there any sort of test (TTY) number one can call to make sure the program is working? Do you guys know about any service where I can look up the phone number so that I know its a correct number. Further I m trying to make call in same state. What is the problem with tty phone?