Matrix SETU VFXTH System Manual 118
• Select the desired Fax Protocol, to send and receive the Fax over IP:
• T.38(UDPTL): If you select this option, the device you are sending the fax to, must also support this 
protocol. 
• T.38(RTP): If you select this option, the device you are sending the fax to, must also support this 
protocol. 
• Pass Through: Select this option if you need to send fax over G.711. The device you are sending 
fax to must also use G.711. 
Default: T.38 (UDPTL).
• If you have selected T.38(UDPTL) or T.38(RTP) as Fax Protocol, you must select an appropriate T.38 
Version that is compatible with your ITSP proxy server/remote peer. You may select:
•0 
•1
•2
Default: 0 
• Select the Convert FAX call to Speech call when FAX is complete check box, if you want SETU 
VFXTH to convert the fax call to a speech (voice) call after the fax complete event is received. Default: 
Disabled.
• If you have selected Pass Through as Fax Protocol, you must select an appropriate Passthrough FAX 
Codec that is compatible with your ITSP proxy server/remote peer. You may select the Codec as:
• G.711(µ-law) 
• G.711 (A-law)
Default: G.711 (µ-law) 
• Select an appropriate Call Hold Method that is compatible with your ITSP proxy server/remote peer. 
You may select:
• RFC 2543
• RFC 3261
Default: RFC 3261 
• Select the Call Hold using Inactive check box, if you want the system to send ‘a=inactive’  message 
instead of ‘a=sendonly’ message on the SIP Trunk, when the user puts the call on hold. Default: 
Disabled.
• Clear the Send Re-INVITE when multiple codec is received in 200(OK) check box, if you do not 
want SETU VFXTH to send Re-INVITE message and use only the first codec from the multiple codec 
received in 200(OK). Default: Enabled.
• Select the Allow Call Disconnection using Access code check box, if you want to enable the feature 
Disconnect Call using Access Code on the SIP Trunk. See “Disconnecting a Call using Access Code”.
• Select Send "user=phone" in SIP URI check box, if you want SETU VFXTH to add user=phone in the 
Request URI/From/To header of the INVITE message. Default: Disabled. 
SETU VFXTH will send user=phone in SIP URI, only if the SIP ID is numeric.