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Hi, I can't make regular voip traffic with an ATA device through the TL-MR6400 router and 3G connection.
I hear the called person voice but he can't hear me. I tried every combination of parameters in port forwarding,trigger ports and DMZ. I also disabled SPI Firewall and SIP ALG.
My mobile internet provider allows voip traffic since with a TL-MR3220 and an usb internet key, everything works fine. It seems that whatever I do in port forwarding,trigger ports and DMZ windows,
the changes are not applied ( there is always the same behaviour ), I tried also a reboot at every change. The telephonic support told me that there is a fw that fix the problem, but I didn't receive nothing from them yet.
Obviously the router has the last fw.
Please help.
Thanks