While you wait for answers, we may have found some information which could help you.
Click here for Telstra Answering MachineTelstra v850a handset reads line in use. Can't get a line?
Telstra 7100A, "Not Registered"?
My caller id is not working?
My cordless phone says Base 1 (Telstra 7100) ?
telstra 6100a with 4 handsets?
call waiting feature on telstra v850a cordless telephone?