Medias Mediatrix 1204, Reference Manual

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Mediatrix 1204 311
A
P P E N D I X
D
Country-Specific Parameters
The following parameters differ depending on the country in which you are.
Definitions
The following are some useful definitions.
Conventions
The following conventions apply to this Appendix.
Frequencies
Symbol “*” means modulated. For instance: 425 Hz * 25 means 425 Hz modulated at 25 Hz.
Symbol “+” means added. For instance: 425 Hz + 330 Hz means that both 425 Hz and 330 Hz
sines are played at the same time.
When a tone is composed of more than one frequency, if not otherwise specified, the given
electrical level applies to each frequency taken separately.
Impedance
Impedance is the apparent resistance, in an electric circuit, to the flow of an alternating current, analogous to
the actual electrical resistance to a direct current, being the ratio of electromotive force to the current.
When representing an impedance, the following applies:
Symbol “ //” means parallel.
Symbol “+” means serial.
Furthermore, there are two types of impedances:
Input Impedance
Terminal Balance Return Loss (TBRL) Impedance
Table 194: Definitions
Term Description
Dial Tone Indicates the line is ready to receive dialing.
Busy Tone Indicates the line or equipment is in use, engaged or occupied.
Ringback Tone Indicates the called line is ringing out.
Special Information Tone Identifies network-provided announcements.
Receiver Off Hook (ROH) Tone Indicates that the telephone is not hung up correctly.
Network Congestion Tone Indicates that all switching paths are busy, all toll trunks are busy, or
there are equipment blockages.
FED Tone Indicates the far end tone detection.