5.5 Telephony

Which Internet connectivity method sends voice phone calls using the TCP/IP protocol over digital data lines?
The presence of unapproved modems on desktop systems gives rise to the LAN being vulnerable to which of the following?
War Dialing
A customer just received a phone bill on which there were charges for unauthorized services. This customer is a victim of which type of attack?
Which of the following phone attacks adds unauthorized charges to a telephone bill?