# Fax Advanced Settings

## Purpose

Use this form to enable interoperability between a V.34 fax machine connected to a MiVoice Business system over SIP trunks to another V.34 fax machine on a 3rd-party SIP gateway.

NOTES

- As with Fax over IP using T.38 between MiVoice Business systems, transmission from the SIP gateway is re-negotiated down to V.17 speeds to improve reliability.

- The settings in this form are applied to all ports on a system.

Use this form for the following tasks:

- Configure FAX Over IP Support

## Field Descriptions

Parameter | Description | Default Value
Enable V.34 Fax Interop at V.17 speeds with SIP GWs | Allows calls from a V.34 fax machine to pass through a SIP gateway to the MiVoice Business system. NOTE: This option allocates additional DSP resources to fax detection leaving fewer resources for other calls. Thus, it should only be enabled if all of the following conditions are true, MiVoice Business is connected via an IP/SIP trunk to a 3rd-party SIP Gateway MiVoice Business and 3rd-party SIP Gateway are each connected to V.34 capable Fax machine. T.38 must be used to transmit faxes between the two Gateways. | Disabled
Enable T.38 FAX Logging | Enables logging of FAX Relay (T.38) calls. The following data is provided in a FAX call log: T.38: Identifies the call as a FAX Relay (T.38) call. No.: Number assigned to the FAX call by MiVoice Business. The FAX call number is a count of the number of T.38 calls that have occurred since MiVoice Business was booted up or reset. You can use this number to track the last FAX call that was made. If you are having FAX call issues, note that last number, attempt a FAX call, and check the result. If the number has increased by one, then you know that the FAX call log is for the FAX call attempt. Note the time of the FAX call and use the time to find the associated SMDR record. After a reboot, the system resets the No. to 1. Pages: Number of pages sent or received. Speed: Modulation and speed of the FAX call. Duration: Length of time in minutes and seconds that it took for the FAX call to complete. Result: Indicates success or failure of the FAX call and provides a result code to assist technical support with debugging. Example FAX call log:
Source: Description: | FAX SP T.38, No. 555, Pages: 2, Type: Send, Speed: V.17 14400 bps, Duration: 0:35, Result: Success (0xC800)
NOTES T.38/Fax logging should only be enabled when Fax logs are required for troubleshooting Fax problems. These logs are written to the system maintenance logs. As of MCD Release 5.0 this setting replaces the maintenance commands called ‘FAX LOG ENABLE’/’FAX LOG DISABLE’ | Disabled
T.38 RX Level | Adjusts the fax receive level. Under normal circumstances the level should be left at the default setting. Improper adjustment may cause Fax transmission errors. CAUTION: Change this setting only under the direction of Mitel Customer Support. | -43 dBm
Fax Detect Level | Adjusts the sensitivity of the Fax detector. Under normal circumstances the level should be left at the default setting. Improper adjustment could cause Fax transmission errors. CAUTION: Change this setting only under the direction of Mitel Customer Support. | -35 dBm
Fax Detect Timeout | Adjusts the time (in seconds) that the Fax detector is actively looking for a CNG tone. Adjustments may be required to reduce the number of false Fax detections. Under normal circumstances the timer should be left at the default setting. CAUTION: Change this setting only under the direction of Mitel Customer Support. | 60 s