SummaryThis Recommendation specifies syntax and semantics of terminal information messages as well as procedures to use them for in-band negotiation at the start of or during communication. The messages cover receiving and transmitting capabilities as well as mode preference from the receiving end, logical channel signalling, and Control & Indication. Acknowledged signalling procedures are specified to ensure reliable audiovisual and data communication. Relative to Version 10 (2003-07) of H.245, this version includes: • support for RFC 3389 – RTP Payload for Comfort Noise; • support for bit rates in multiple payload stream; • L16 Capability Definition; • resolution of H.245 Open Logical Channel Conflicts; • definition of a minimum audio packet rate; • ITU-T Rec. H.235 Annex G "Usage of the MIKEY key management protocol for the secure real time transport protocol (SRTP) within H.235"; • compact H.245 Capabilities Expressions; • generic capability for Nx64K Circuit Relay over IP; • update of Resolution of H.245 Open Logical Channel Conflicts; • call reset procedure in ITU-T Rec. H.324. Products claiming compliance with Version 11 of H.245 shall comply with all of the mandatory requirements of this Recommendation. Version 11 products can be identified by H.245 TerminalCapabilitySet messages containing a protocolIdentifier value of {itu-t (0) recommendation (0) h (8) 245 version (0) 11}. |