Answer Supervision; Sip Application - Soundwin VoIP Voice Gateway User Manual

C Answer supervision
This is designed to help explain and resolve issues of answer supervision from a switch or
PSTN provider that could result in billing for termination calls.
Gateway provides 2 Types of Answer Supervision:
1. Loop-Start Reverse Battery, Reverse battery (also called Polarity Reverse) is when the PSTN
provider reverses the polarity of the battery voltage, for both answer supervision and disconnect
supervision.
2. Voice Detection-based answer supervision is a feature where the Gateway can be configured
to "listen" on the line for different tones and voice. The Gateway sends a "connect" signals out or
"disconnect" signaling using internet.

SIP Application

Case 1: Loop Start Reverse Battery : PSTN Line was set Polarity Reverse:
The gateway can send the "200 OK" SIP signals to Billing System of ITSP, after the user pick
up the Phone and detect the PSTN line answer voltage.
The gateway can send the "200 BYE" SIP signals to Billing System of ITSP, after the user hang
up the Phone and detect PSTN line disconnect voltage.
Case 2: Voice Detection based on answer supervision:
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