Instruction manual
Security risks
4-8 Issue 9 May 2003
General security measures
General security measures can be taken system-wide to discourage unauthorized 
use.
Educating users
Everyone in your company who uses the telephone system is responsible for 
system security. Users and attendants need to be aware of how to recognize and 
react to potential hacker activity. Informed people are more likely to cooperate 
with security measures that often make the system less flexible and more difficult 
to use.
■ Never program passwords or authorization codes onto auto dial buttons. 
Display phones reveal the programmed numbers and internal abusers can 
use the auto dial buttons to originate unauthorized calls.
■ Discourage the practice of writing down passwords. If a password needs to 
be written down, keep it in a secure place and never discard it while it is 
active.
■ Attendants should tell their system manager if they answer a series of calls 
where there is silence on the other end or the caller hangs up.
■ Users who are assigned voice mailboxes should frequently change 
personal passwords and should not choose obvious passwords (see 
‘‘Choosing passwords’’ on page 4-5
).
■ Advise users with special telephone privileges (such as remote access, 
voice mail outcalling, and call forwarding off-switch) of the potential risks 
and responsibilities.
■ Be suspicious of any caller who claims to be with the telephone company 
and wants to check an outside line. Ask for a callback number, hang up, 
and confirm the caller’s identity.
■ Never distribute the office telephone directory to anyone outside the 
company; be careful when discarding it.
■ Never accept collect phone calls.
■ Never discuss your telephone system’s numbering plan with anyone 
outside the company.










