DESC

PSTN Type I & Type II Caller ID services simulator

DESC is a complete solution to design and test equiments capable of receiving Caller ID signals. A programmable telephone interface gives the user control over various parameters including tone, FSK and ring levels, DTMF selection and line polarity.

This allows the DESC to simulate the real conditions that CPE's are likely to encounter for both on-hook (CID) and hoff-hook (CIDW) data transmission. All the audio signals are processed and generated.

Complex or automated testing sequences are simplified and can be saved or recalled at any time. A library of tests can then be used to fully qualify the compliance of both the equipment and software under test.

The DESC software runs under Windows and provides an easy access to the controls.

DESC complies in full with ETS 300 659-1, ETS 300 659-2, CCITT Rec. V23, CCITT Rec. T.50 regulations

DESCRIPTION

DESC includes :

A serial port for data transfers to a PC
1 output for Caller ID Terminal Equipment connection
1 output for standard Terminal Equipment connection
1 BNC input for signals injection

FEATURES

-3 LEDs to display DESC power supply, Terminal Equipment ringing and audio signals

- Any testing sequence can be simulated with possibility to modify the message timings and message structure :

- Off-hook during ringing sequence First Ring Pattern - T0 Silence - Channel Seizure Signal - Mark Signal - T1 Silence - Second Ring Pattern

- Off-hook prior to ringing sequence TE Alerting Signal - T0 Silence - Channel Seizure Signal - Mark Signal - ringing pulse

-On-hook sequence Subscriber Alerting Signal - Ta Silence - Tb Silence - TE Alerting Signal - Tc Silence - TE-Ack - Td silence - Mark Signal

- Message structure
Date and time - Calling Line Identity or Reason for absence of CLI - Called Line Identity - Calling Party Name - Reason for absence of CPN - Complementary CLI - Call type - First Called Line Identity - - Network Message System Status - Type of Forwarded call - Type of Calling User - Redirecting Number - Extension for network operator use

Testing sequences can be edited and altered in text or hexadecimal mode
Testing sequences can be chained in continuous or step by step mode

- Telephone line loop voltage : 48 V.
- Ring generator : 16 to 50 Hz
- FSK generator : -40 dBm to 0 dBm
- DTMF generator

MASC

PSTN Type I & Type II Caller ID services analyzer

The benefits of the Caller ID messages can only be gained if the transmission quality and the services are enabled and working to a satisfactory level.
Connected in parallel to the Public Switched Telephone Network, MASC captures the traffic, decodes and displays all the signaling information relating to the Caller ID informations for both on-hook (CID) and off-hook data transmission (CIDCW).

Designed to be left on site or transferred from site to site, MASC can be used for both the real-time reporting and local data-capture.

MASC complies in full with ETS 300 659-1, ETS 300 659-2, CCITT Rec. V23, CCITT Rec. T.50 regulations

DESCRIPTION

MASC includes :
- A serial port for data transfers to a PC
- 1 PSTN line interface

FEATURES

- LEDs to display MASC power supply and the ring pattern
- Recording of CID & CIDCW messages in MASC memory (64 Kbytes)
- Display on PC
- Posssibility of resetting MASC memory
- Possibility of requesting all messages held in MASC memory from a specific date, or from the oldest message on.
- Possibility of purging files according to name, or date and time of file beginning and end
- Real time & log displays :
- Caller ID : Line reversal - T0 silent period - TE Alerting Signal - Silent period - Seize - Mark Signal - Message type - Message length - Date & time - Calling Line Identity - Checksum
- Caller ID on Call Waiting : Subscriber Alerting Signal - Ta + Tb Silence - TE Alerting Signal - Time-out - TE-Ack - DTMF code - Td silence - Mark Signal - Message type - Message length - Date & time - Calling Line Identity - Checksum
- Filtering from message types (CID, CIDCW), V23 messages (text, hexadecimal)
- Research criteria selected either according to file name or date and time of file beginning and end
- Output destination : printer, ASCII file

Présentation du DTMF

Le DTMF ( Dual Tone Multi Frequency ou "Fréquences Vocales" )est un procédé de numérotation qui génère des sonorités codées ( et non des impulsions comme les cadrans rotatifs ).

Le tableau ci-dessus montre qu'à chaque touche correspond une paire de fréquences appartenant l'une au "groupe haut" et l'autre au "groupe bas". Ces paires de fréquences sont normalisées au plan international. Chacun de ces groupes contenant 4 fréquences, 16 combinaisons sont possibles: les chiffres 0 à 9, l'étoile, le dièse, et les touches ABCD.

Le principe du DTMF consiste à superposer 2 fréquences sinusoïdales correspondant à la paire de fréquences de la touche appuyée :
ex. : le chiffre '4'correspond à la somme des fréquences (770 Hz+1209 Hz)