1
Scope
2 References
2.1 Normative references
2.2 Informative references
3 Terms and definitions
4 Abbreviations
5 Bearer capabilities for which echo
control is required
6 Arrangements of echo control
devices with respect to signalling
7 Operation without signals
8 Considerations for the need of
ECDs
8.1 Information taken into
consideration
8.2 Propagation delay counter, call
history information
9 Functions of an exchange
initiating echo control
10 Unavailability of echo control devices
11 Placement of echo control devices in the network
12 Handling of echo control devices in the case of different bearer
capabilities
13 Other considerations
Annex
A – Echo control logic
A.1 General principles and definitions
A.2 Abstract model
A.3 SDL diagrams
Appendix I –
Transmission of echo control information elements via signalling systems