Modifying FAX Relay Profile Settings
From TBwiki
Applies to version v2.10
To configure FAX Relay settings, do the following:
1- Click Fax Relay in the Editing Profile window, to display the customizable options.
2- Modify settings as required.
3- To configure NSE, check the Use NSE checkbox.
NOTE:
If NSE exchange is possible (negociated in the SDP), the switch to passthrough will happen in the RTP stream and no longer wiil occur with a SIP re-INVITE. This implementation of NSE currently only supports a switch to passthrough, which means that you can have NSE packets switching to T.38.
- Click Save
Path
/configurations/@[configuration_name]/profiles/@[profile_name]
Parameters (text)
/configurations/@[configuration_name]/profiles/@[profile_name] name = "@[profile_name]" /configurations/@[configuration_name]/profiles/@[profile_name]/voip/fax_modem_relay/t38_parameters fill_bit_removal = false max_bitrate = "14400" redundancy_count = 0 transmission_level_minus_dbm = 10 use_v34 = false
Parameters (json)
{
"voip" : {
"fax_modem_relay" : {
"detection_mode" : "Standard",
"enable_early_fax_modem_tone_detection" : false,
"enable_fax_modem_relay" : true,
"expected_cng_tones" : 2,
"fax_modem_passthrough_parameters" : {
"codec" : "PCMU",
"detection_type" : "Silence suppression off",
"force_v152_vbd" : false,
"jitter_buffer_depth" : 40,
"packet_duration" : "20ms",
"support_v152_vbd" : false,
"use_nse" : false
},
"fax_modem_tones_detection_duration" : "30 seconds",
"modem_vs_fax_distinction_timeout" : "0 millisecond",
"relay_mode" : "T.38",
"switch_to_fax_relay_upon_cng_tone" : true,
"switch_to_passthrough_upon_bell_ans" : true,
"t38_parameters" : {
"fill_bit_removal" : false,
"max_bitrate" : "14400",
"redundancy_count" : 0,
"transmission_level_minus_dbm" : 10,
"use_v34" : false
}
}
}
List of Parameters
Fax/Modem Relay
- Enable Fax/Modem Relay
- Detection Mode
- Relay Mode
- Modem vs. Fax distinction timeout
- Fax/Modem tones detection duration
- Enable early Fax/Modem tone detection
- Enable switching to FAX relay upon CNG tone
- Switch to passthrough upon Bell ANS
T.38 Parameters
Fax/Modem Pass-through Parameters

