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Enable SRTP (Secure RTP)

Overview​

SRTP (Secure Real-time Transport Protocol) encrypts audio and video media packets transported over RTP.

In ITVDesk, the Enable SRTP option applies when adding an ONVIF IP Camera and controls media-plane encryption, not device control.

SRTP protects the actual media stream against:

  • Eavesdropping
  • Packet inspection
  • Man-in-the-middle attacks

What SRTP Protects​

SRTP encrypts:

  • RTP video packets
  • RTP audio packets

SRTP does not encrypt:

  • RTSP control commands
  • ONVIF SOAP/XML communication

SRTP operates only on the media layer.

How SRTP Works in ITVDesk​

When Enable SRTP is enabled:

  • Media streams are negotiated using SRTP
  • Encryption keys are exchanged during RTSP/SDP negotiation
  • Audio and video are transmitted in encrypted RTP packets

RTSP signaling may still use:

  • RTSP
  • RTSP over TCP
  • RTSPS (if enabled separately)

Relationship to ONVIF​

SRTP is negotiated through ONVIF Media profiles:

  • ONVIF client requests secure media transport
  • ITVDesk advertises SRTP capability
  • Both sides must support SRTP

If the ONVIF client does not support SRTP:

  • Connection may fail
  • Or fallback to non-encrypted RTP (depending on client behavior)

When to Enable SRTP​

Enable SRTP when:

  • Media confidentiality is required
  • Streams traverse untrusted networks
  • Security policies mandate encrypted media
  • Audio/video must not be exposed on the network

Typical environments:

  • Enterprise networks
  • Government installations
  • Public or shared infrastructure

When NOT to Enable SRTP​

Avoid enabling SRTP when:

  • Using legacy NVR/VMS systems
  • Compatibility is more important than encryption
  • Performance is critical on low-power systems
  • Multicast streaming is required (SRTP multicast is not supported)

Compatibility Notes​

  • SRTP support varies across VMS/NVR systems
  • Some clients support RTSPS but not SRTP
  • Some clients support SRTP only with TCP interleaving
tip

Always test compatibility before enabling SRTP in production.

Performance Impact​

  • Slightly higher CPU usage
  • Increased latency compared to plain RTP
  • Reduced packet inspection capability

Impact is usually negligible on modern systems.

Summary​

The Enable SRTP option in ITVDesk:

  • Encrypts audio and video media packets
  • Protects media confidentiality
  • Is negotiated via ONVIF and RTSP
  • Is independent of RTSPS and ONVIF HTTPS

Use SRTP when media security is required, but verify client compatibility.

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