...
supports The existing DTLS-SRTP
support and is
enhanced extended to allow a relay mechanism that transparently passes the DTLS, SRTP
, and SRTCP packets end-to-end without DTLS certification or SRTP cryptographic encryption and decryption taking place at SBC. When SBC is configured to relay DTLS-SRTP, the endpoints establish DTLS association using each other’s credentials, which are transparently passed by SBC in the SDP of the SIP signaling messages. Encryption and decryption of the SRTP and SRTCP packets take place at the endpoints based on the cryptographic credentials passed through DTLS.
If media transcoding, DTMF interworking or Lawful Intercept (LI) processing is required on the session, as determined during the initial invite or offer call negotiation stage DTLS-SRTP is not relayed....