1 Scope
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
5.1 Recommendation version
5.2 SDP Offer/Answer protocol variants
6 Definition of the VBD mode of operation
6.1 Minimum requirements for VBD mode of operation
6.2 Echo canceller and VBD mode
6.3 IP transport services for VBD
7 Negotiation of support of VBD and selection of VBD codec and other VBD
enhanced functionality
7.1 Negotiation using the session description protocol
7.2 Use of VBD in ITU-T H.323 systems
7.3 Mid-call negotiation using session description protocol
8 The use of IETF RFC 4733 modem/facsimile/text telephone events
9 VBD stimuli
10 Procedures for transitioning between audio mode and VBD mode
10.1 Procedures for state transitioning
10.2 State machine – Overview
10.3 Enforced state transition by call/session control
11 Optional procedures for indicating to a remote end transition into VBD
using state signalling events
11.1 Declaration of SSEs
11.2 Transition to the VBD mode for ITU‑T V.150.1
gateways
11.3 Transition to the VBD mode for non- ITU‑T V.150
cases
11.4 Transition from the VBD media mode
11.5 Security – Optional
Annex A – Vendor-defined messages
Annex B – Use of data signal detection and silence insertion in voiceband
data
B.1 Introduction
B.2 Guideline for the use of DSD
B.3 Negotiation of the DSD capability with SDP
B.4 Negotiation of the DSD capability with [ITU‑T H.245]
Annex C – Use of ITU‑T V.21 preamble for echo canceller control in
an ITU‑T V.152 gateway
Bibliography