User manual
Default value is: 3 seconds (3000ms)
4.5.12 Polarity Reversal for Metering
Some applications such as pay phones and billing systems require polarity reversal to occur in a predened
interval for correct billing calculation.
You can enable Metering polarity Reversal on each FXS port and Polarity Reversal will occur every 60
seconds (60 seconds is default). It can be adjusted to a lesser or grater time interval.
4.5.13 Conguring Caller ID
4.5.13.1 Caller ID Overview
Caller ID is the CLASS service of PSTN simulator which delivers the calling party phone number and name to
the telephone set of the called party. This service gives the called party ability to identify caller by telephone
number or name even before answering the phone or when is on call with a third party.
North American Caller ID services were dened by BellCore. The documents GR-30-CORE and SR-TSV-
002476 specify the voice-band data transmission which governs the interface for Caller ID (Type I) and Caller
ID on Call Waiting (CIDCW). CIDCW is also called Type II application where the data transmission is under the
off-hook condition.
GR-30-CORE, Voice-band Data Transmission Interface, can be used for references for Caller ID and its
protocol. It describes the standard modem-based technology from an SPCS (Stored Program Controlled
Switching System) to a CPE (Customer Premises Equipment). It provides some of the lower-layer
requirements of the CID protocol. SR-TSV-002476, CPE Compatibility Considerations for the Voice-band Data
Transmission Interface, denes requirements for CPE compatibility with GR-30-CORE. It addresses signaling
protocol, data transmission, signaling detection and generation, and design consideration.
4.5.13.2 Caller ID Type I and Caller ID Type II
Two types of Caller ID are available for conguration. Caller ID Type I is the service when caller information
is delivered when called telephone is on hook. Caller ID Type II is the service when caller identity is delivery
to the called party while called party is engaged in a call with a third party. This type of Caller ID also know as
"Caller ID on Call Waiting" or CIDCW.
Caller ID type I is a subset of Type 2.
4.5.13.3 Caller ID multiple or single message
Single Data Message Format (SDMF) or Multiple Data Message Format (MDMF) denes which
information delivered to the called party as a part of Caller ID Data message.
SDMF delivers date, time and a calling number.
MDMF delivers date, time, calling number and a caller’s name.
4.5.13.4 Caller ID Data
Caller ID data consists of date, time, caller’s phone number and a caller’s name
4.5.13.5 Reasons for absence of Caller ID information
Caller ID information is not always can be presented to the called party. Due to a lack of SS7 signaling in
some areas, calling number cannot be exchanged among telephone switches. In this case called party will
have an "Out of Area" message instead of the calling party phone number.
24
User Manual
Public Switched Telephone Network (PSTN) Simulators