D-Link voip ta dvg-5112s User Manual

DVG-5112S User’s Manual                                                                                                 
 

D-Link Systems, Inc.                                                                                                                                                        31 
 

 

 

 
 

  T.38: The T.38 protocol is used for better and faster facsimile transmission. So it is recommended to 

enable this function to gain better fax quality. When this function is enabled, please select UDP or TCP. 
If you select TCP and some gateways cannot use the fax function, please select UDP instead. 

  NOTE: When a fax tone is detected in a call, the gateway will automatically switch from voice mode to 

fax mode. So fax settings will be temporarily applied to a specific port which detects fax tones, instead 
of its default voice settings. 

  Enable High Quality: The system sends the same fax frame twice to get a high quality fax 

transmission. Enabling this variable increases bandwidth requirements. 

  T.30: The system uses T.30 as the protocol for fax transmission. The parameter settings are the same 

as for voice transmission. However, enabling the T.30 protocol will consume more network resources 
and will affect transmission quality.   

  NOTE: When you send fax over an IP network it needs your network to support fax over IP 

functionality (either T.38 or T.30). Please consult your VoIP service provider for this setting.