Automatically Switching to T.38 Mode without SIP re-INVITE

In the Automatically Switching to T.38 mode without SIP re-INVITE, when a fax signal is detected, the channel automatically switches from the current voice coder to answer tone mode and then to T.38-compliant fax relay mode.

To configure Automatic T.38 mode:
1. Open the Gateway General Settings page (Setup menu > Signaling & Media tab > Gateway folder > Gateway General Settings), and then from the 'Fax Signaling Method' drop-down list (IsFaxUsed), select No Fax:

2. On the Fax/Modem/CID Settings page, configure the 'Fax Transport Mode' parameter to T.38 Relay [FaxTransportMode = 1].
3. Configure the following optional parameters:
'Fax Relay Redundancy Depth' [FaxRelayRedundancyDepth]
'Fax Relay Enhanced Redundancy Depth' [FaxRelayEnhancedRedundancyDepth]
'Fax Relay ECM Enable' [FaxRelayECMEnable]
'Fax Relay Max Rate' [FaxRelayMaxRate]