thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Collaboration, Voice & AV · Advanced

Datagram Transport Layer Security for SRTP (DTLS-SRTP)

A key exchange method (RFC 5764) that performs a DTLS handshake on the media path to derive SRTP keys.

Definition

With DTLS-SRTP, endpoints exchange certificate fingerprints in SDP and then perform a DTLS handshake over the same UDP ports as media, so keys never appear in signaling. It is mandatory in WebRTC and used by many cloud platforms. Gateways may need to interwork DTLS-SRTP with SDES when connecting to SIP systems.

Example

A browser and a WebRTC gateway verify a=fingerprint values in SDP and complete a DTLS handshake before media flows.

Exam tip

WebRTC uses DTLS-SRTP; traditional SIP trunks usually use SDES with TLS.

Related terms