undertaking difficulties to connect / error 619 / error 721

by Ron Wolpa - 3/8/09 10:44 AM

Hello,
I have an unlimited internet service and have experienced difficulty in getting a dial up conection. Usual errors that come up after the modem handshaking are errors 619 and sometimes error 721.
It may seem strange that the trouble seems to be related to specific hours of the day. During the morning it is more likely to get a connection but during the afternoon or the evening the problem occurs. Ive already purchased a new modem despite the other one works exactly the same way. The problem remains with the brand new modem.
Ive contacted ISP who states nothing is wrong and suggested me to contact the phone company who is very limited in terms of tests to be run to check the line (the phone company only checks if the line is operational for voice).
Ive heard from a IT engineer that he had the same problem and that he never found a solution what makes it seem that this is more common than I think.
Any suggestion to figure out this?
Thank you very much