I bought one GXW-4104 and it is working OK with my trixbox / Asterisk pbx.
The only issue I have is with the way the trunk is selected.
I read in the manual and the device works in round robin, this makes my life complicated, since I have one CO, the second one is a PBX line and the third one is a cellular line with “Dock-n-telâ€
round robin is selected or isn’t based on how you dial it.
you can specify a group by doing something like
Zap/G0/yournumbertodial
or specify an individual zap channel
Zap/3/yournumbertodial
will dial out on zap channel 3 and none other. if zap/3 isnt available the call will fail.
YOu can also use zapata.conf to set up zap groups, so you can have many channels for each type of line…
does that help?