Outbound SIP Trunk Security

When exposing a SIP application to the public internet, it is essential to implement strong security measures to prevent unauthorized access. Poorly secured VoIP systems are frequent targets for malicious attacks.

DIDWW Outbound SIP Trunks provide two layers of authentication for enhanced security:

• Digest Authentication (mandatory): All SIP requests are challenged and must be authenticated with a username and password.

• IP-Based Authentication (optional): Calls are only accepted when originating from authorized IP addresses.

Additional protective measures include:

• 24-hour spending limit: Defines the maximum allowed expenditure per trunk in a rolling 24-hour window. Once reached, outbound traffic is blocked until manually re-enabled. Active calls are not disconnected and may exceed the set threshold.

• Capacity limit: Restricts the maximum number of simultaneous calls per trunk.

Recommended Best Practices

1. Regularly review call traffic: Monitor call logs and compare activity across different timeframes to detect unusual patterns or misuse.

2. Restrict international calling and enable geo-fencing: Limit outbound calls to approved countries and use firewalls or geo-fencing to block high-risk regions.

3. Keep VoIP devices updated and secure: Regularly update firmware, use routers or firewalls, and change default administrative passwords to close vulnerabilities.

4. Use VoIP-specific firewalls: Deploy firewalls designed for VoIP to block unauthorized access and optimize call quality.

5. Educate users on security practices: Train users to follow proper credential handling and recognize abnormal call behavior to help detect potential breaches early.