This Tech Tip offers best practices for protecting customers from unauthorized access to their NEC phone systems. Without proper safeguards, a hacker could exploit a mailbox’s Find-Me/Follow-Me feature to redirect calls to international numbers.
Suggestions to Prevent Unauthorized Use of Find-Me/Follow-Me
Have Users Password Protect Their Mailboxes
- From the user’s mailbox menu, dial
67 - Dial
7to change the security code
- The security code must be 4 digits long
⚠️ Tip: Avoid using passwords that are easy to guess, such as 1111, 1234, or the user’s extension number.
Set Unused Mailboxes to “Undefined” or “None”
1. Protect Station Mailboxes
- Go to Program 47-02-01: InMail Station Mailbox Options
- Use the Mailbox (1~28) search box to locate the unused mailbox
- Set Mailbox Type to:
- “Undefined” for SL1100
- “None” for SL2100
2. Protect Group Mailboxes
- Go to Program 47-03: InMail Group Mailbox Options
- For each unused Group Mailbox, set the Mailbox Type to:
- “Undefined” for SL1100
- “None” for SL2100
Apply Toll Restriction to InMail Ports
It’s recommended to apply Toll Restriction to all InMail ports that block International Calling. By doing this, even if a hacker was to take over a mailbox, the attempt to call out to an International number will fail.
⚠️ Tip: If your phone system was purchased from us with a pre-programmed database, International Toll Restriction is already applied to Class 2, and the steps below are complete.
If you did not purchase your phone system from us with a pre-programmed database, please complete the steps below
1. Assign InMail Ports to a Restricted Class
- Go to Program 21-04: Toll Restriction Class for Extensions
- Set all InMail Ports to Toll Class 15 for all system Modes
2. Configure the Restriction Table
- Go to Program 21-05: Toll Restriction Class
- Use the Toll Restriction Class (1~15) search box to select Class 15
- Set International Call Restriction Table to:
Assigned
3. Add International Blocking Rules
- Go to Program 21-06-01: International Restriction Table
- For Table Entry 01, set Dial Digits to:
011
⚠️ Tip: By default, all extensions are assigned to Toll Restriction Class 2, which references both the International Toll Restriction Table and the International Toll Permit Table. The steps above will also block international calling for Class 2.
If a user needs to make international calls but still wants to block InMail from doing so:
- Permit only specific 011 + country code entries, or
- Disable Program 21-05-01 for the Toll Class used by those telephones