Overview

This article provides information about faxes that fail using a fax over IP (FoIP) fax device.  When reviewed in a Wireshark Capture you see the error "488 Not Acceptable Here" and could be an Unknown Error 03, Handshaking Failure 54, or a Call Failed 46 in the FaxMaker Monitor or logging.  The steps in the solution section will give guidelines for resolving this error.  

Environment

Any FaxMaker system using a FoIP fax device.

Solution

The FoIP devices that work with FaxMaker are the Brooktrout SR140 and XCAPI.  There are some Brooktrout physical cards that can facilitate FoIP as well, ones with a 1N designation in the model number, and they are configured the same way as the SR140.   

When the "488 not acceptable here" is given when the wrong transport method is configured.  The two transport methods to choose from are T.38 and G.711.  The error is given because the gateway and the fax devices are trying to use different transport methods and the two are not compatible with one another.  

Generally, faxes start using G.711 and if supported will switch to T.38 while setting up the media session, before progressing to the T.30 protocol part of the call  The issue arises when one side is set to use one transport method and the other is not.  

For example, the sender starts the call with G.711 and is configured for only G.711 and the recipient tries to shift the call to T.38.  Since the sender is not able to use T.38 it will give the "488 Not Acceptable Error".  This can be given by the sender or the recipient.  

When configuring the fax transport, the gateway the fax device connects to and the fax device must be configured to use the same transport.  If the gateway is set for G.711 only, then the fax device must be set the same way.   No one specific setting will work for every fax device,  but it will depend on your fax device setting and environmental factors.  

Configuring the Brooktrout SR140 for G.711 or T.38

1. From Programs,  open the Brooktrout Configuration Tool by right-clicking and run as administrator.
   
   
2. If the Brooktrout Configuration Wizard appears, select the advanced mode button on the bottom left.
   
   
3. If the Brooktrout Configuration Tool preferences box appears, select OK.
   
   
4. Expand IP Control Modules, in the left pane and select SIP or H.323 depending on your configuration.
   
   
5. Select the T.38 Parameters tab.
   
   
6. The first dropdown is the Fax Transporting protocol and the options are shown in the screenshot below.  Set this to the same setting as the gateway that this device communicates with.  
   
   
   
   
7. Upon completion of the configuration settings change, select Save and Apply from the top ribbon to save the settings and restart the Brooktrout Boston service.  
   
   
8. Finally, restart the FaxMaker fax server service from the services.msc.  

Configuring XCAPI for G.711 or T.38

1. From programs, open the XCAPI Configuration
   
   
2. From the top ribbon, select expert mode
   
   
3. Expand Controller
   
   
4. Expand your specific controller type
   
   
5. Select the Fax node
   
   
6. On the Options tab, the first option is the fax transport (called Fax Method in XCAPI) and the options are shown in the screenshot below.  Set this to the same setting as the gateway that this device communicates with.  
   
   
   
   
7. Upon completion of the configuration settings change, select Save from the top ribbon to save the settings.
   
   
8. Finally, restart the FaxMaker fax server service from the services.msc.  

Confirmation

Once the fax transport settings are set to match your fax gateway's settings the "488 Not Acceptable Here" error will no longer occur.