Voice API Programming Guide — June 2005 21
Product Description

1.6.6 Echo Cancellation Resource

The echo cancellation resource (ECR) feature enables a voice channel to dynamically perform echo
cancellation on any external TDM bus time slot signal.
Note: The ECR feature has been replaced with continuous speech processing (CSP). Although the CSP
API is related to the voice API, it is provided as a separate product. The continuous speech
processing software is a significant enhancement to ECR. The continuous speech processing
library provides many features such as high-performance echo cancellation, voice energy detection,
barge-in, voice event signaling, pre-speech buffering, full-duplex operation and more. For more
information on this API, see the Continuous Speech Processing documentation.
See Chapter8, “Recording and Playback” for more information about the ECR feature.
1.7 Send and Receive FSK Data
The send and receive frequency shift keying (FSK) data interface is used for Analog Display
Services Interface (ADSI) and fixed-line short message service, also called small message service,
or SMS. Frequency shift keying is a frequency modulation technique to send digital data over
voiced band telephone lines. ADSI allows information to be transmitted for display on a display-
based telephone connected to an analog loop start line, and to store and forward SMS messages in
the Public Switched Telephone Network (PSTN). The telephone must be a true ADSI-compliant or
fixed line SMS-compliant device.
See Chapter10, “Send and Receive FSK Data” for more information on ADSI, FSK, and SMS.
1.8 Caller ID
An application can enable the caller ID feature on specific channels to process caller ID
information as it is received with an incoming call. Caller ID information can include the calling
party’s directory number (DN), the date and time of the call, and the calling party’s subscriber
name.
See Chapter11, “Caller ID” for more information abou t this feature.
1.9 R2/MF Signaling
R2/MF signaling is an international signaling system that is used in Europe and Asia to permit the
transmission of numerical and other information relating to the called and calling subscribers’
lines.
R2/MF signaling is typically accomplished through the Global Call API. For more information, see
the Global Call documentation set. Chapter1 5, “R2/MF Signaling” is provided for reference only.