Reference10:Interfaces/FXO/Physical
The physical settings of the analogue FXO interfaces can be made here:
| Receive gain: | Set the loudness a user receives at this interface. Defaults to 10dB, range 0dB to 12dB. |
| Transmit gain: | Set the loudness a user transmits at this interface. Defaults to 3dB, range 0dB to 9dB. |
| Flashtime: | Define the duration of flash-hook signal generated by the FXO on demand of the voip peer side. Possible values : 100ms, 200ms 300ms, defaults to 300ms. |
| Cadence Ringpause: | Define the maximum allowed duration of the ring-off pause between AC ring-on pulses of the cadence. Possible values : 5000ms, 5300ms, 5800ms, 6300ms, 7500ms, 8300ms, 9300ms, defaults to 5000ms.
Most countries are covered with the default setting of 5000ms, but there are few countries that use longer pauses. Please see table below. |
| Country specific impedance synthesis: | Set the line impedance for different countries. 'GlobalImpedance' is intended to be used with countries that are not present in the list and that have no known similarities to mentioned countries. |
| Mark calls with first AC ring pulse above [x] milliseconds as [internal/external] calls: | You can define a threshold time to distinguish calls with short first ring pulse (normally internal calls) from calls with longer first ring pulse. You can chose values in steps of 100ms with range 0 up to 1200ms. Defaults to 500ms. Note that the resulting call will be delayed with exactly the given milliseconds if the first ring pulse has proven longer than the given time. The value 0 is a valid value and switches off the time measurement and the call will be established without any delay as internal or external. |
Country specific AC Ringing Cadences
| Country | Frequency[Hz] | on time [msec] | on time Tolerance [+/-msec] | off time [msec] | off time Tolerance [+/-msec] |
| Austria | 40-55 | 1000 | 200 | 5000 | 1000 |
| Denmark | 25 | 750 | 150 | 7500 | 1500 |
| Finland | 22-28 | 1000 | 100 | 4000-5000 | |
| Germany | 23-28 | 250-6500,790-1100 | 3500-5500 | ||
| Iceland | 22-28 | 1200 | 4700 | ||
| Luxembourg | 25 | 1000 | 100 | 4000-5000 | 400-500 |
| Norway | 23-27 | 800-1100 | 2800-4700 | ||
| Portugal | 15-30 | 1000 | 200 | 5000 | 1000 |
| Sweden | 23-27 | 1000 | 100 | 5000 | 500 |
| Switzerland | 22-27 | 1000 | 200 | 4000 | 200/-500 |
Receive and transmit side
| FXO Gateway representing phone | ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::direction::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: | central office/PABX |
| phone speakerphone | <<<<<<<<<<<<<<<<<<<<<<<<<<<<<----receive direction----<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< | PCM DAC |
| phone microphone | >>>>>>>>>>>>>>>>>>>>>>>>>>>>>----transmit direction---->>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> | PCM ADC |
Explanation of Flash and R
Flash and R are used as equivalents. Sometimes hook-flash is also used. Often phones have an R key, but the meaning is all the same.
From a technical point of view Flash is a short interruption in offhook loop-current. You can imagine Flash as a very short hook-on/hook-off event. The on-hook duration of a Flash event is normally between 100ms and 300ms. A Flash on the FXO port will be performed only when the connected voip peer sends a special rtp-dtmf digit code 16d/10h. A flash can only be generated in the connected state, when both sides can hear each other. Flash or R can never be part of a dialing number, like sometimes seen on fax machines.
The innovaphone FXO ports do NOT support dialing with pulses.
Pinout of the a/b connector
| Pin | Function |
| 3 | TIP |
| 4 | RING |