scope:

Datagram transport layer security (DTLS) protocol [b-IETF RFC 4347] and [IETF RFC 6347] is derived and thus aligned with the transport layer security (TLS) protocol [IETF RFC 5246]. There are consequently many commonalities between the control of DTLS bearers and TLS bearers in ITU-T H.248 gateways.

ITU-T H.248-controlled TLS bearers are subject of [ITU-T H.248.90] and [ITU-T H.248.91].

The purpose of this Recommendation is to define usage of [ITU-T H.248.90] for DTLS bearers. It includes in particular:

- description of DTLS specific use cases;

- modelling information;

- description of MG bearer plane differences between DTLS and TLS;

- usage of TLS-defined ITU-T H.248 packages for DTLS bearer types; and

- an extension package for the specific application of DTLS-SRTP [IETF RFC 5764].

Appendix I provides a non-exhaustive list of example use cases for DTLS in two slightly different areas of applications:

1. DTLS as "transport security" means for "DTLS-over-L4" or "L4-over-DTLS" IP bearer traffic; and

2. DTLS as "key exchange" means for RTP/L4/IP bearer traffic using media security according to the secure real-time transport protocol (SRTP).