SIP Security — Best Practices
Authentication
- Use SIP passwords of at least 20 random characters
- Never reuse the same credentials across multiple services
- Change default credentials immediately upon delivery
Encryption
- Enable SIP TLS (port 5061) for signalling
- Enable SRTP for audio stream encryption
- Check that your 3CX or Asterisk PBX supports these protocols
Fraud protection
- Limit allowed destinations (country whitelist)
- Configure usage alerts (Client Area → Notifications)
- Enable the simultaneous call cap
- Block high-risk prefixes: +900, +1900, premium-rate numbers
Monitoring
Review your CDRs daily during the first few months to detect any usage anomalies.
