I tried to register my 4 Grandstream IP phones for hours without succeed.I tried several times, conditions, by following vidéos etc ....
After 1 day, I tried to desactivate the firewall of the S20 in the security section and all the IP phones registrated immediatly. I tried the reverse manipulation and all the IP where no more visible in the supervision section.
I'm now able to communicate with my FXO but the firewall must be desactivate. Could you please explain how to work with these phones without desactivate the firewall ?
Another problem with these phones : Impossible to push an firmware upgrade. I tried to dowload the latest 1628 firmware and put it in the upgrade section on S20 but when the phones reboot, no upgrade occurs. I'm still in 18.104.22.168 as the last upgrade is 22.214.171.124.
Could you pleaase help me ?
Thanks a lot.