We are using Site-to-Site VPN connectivity from India to UK using SonicWALL NSA 2400 firewalls.
India Network - 172.16.0.0/23
UK Network - 10.0.0.0/23
Site-to-Site VPN works fine no issues with network connectivity or accessibility with devices
We are using Avaya IP Office 500 telephone system unit at India site where all India Avaya IP Phones
are connected to India Avaya IP Office. Phones get IPs from India Avaya telephone system.
Our Avaya IP Office is configured to pass all calls to UK Avaya IP Office. e.g. our calls goes to UK from India telephone system-->UK Telephone System-->in/out side UK calls.
Daily I get error on my India IP Phones when I am dialing any extension or number in UK e.g. UNOBTAINABLE
To resolve this issue I have to RESET VPN tunnel (Un-tick and Tick again VPN check box on SonicWALL) everyday to start calling to UK.
India site is also connected to other different sites over Site-to-Site VPN terminology where we are only accessing DATA. These tunnels I never had to reset or had any issues with network connectivity.
I would like to know if anyone has come across this type of issue or experts can advice how I can make it permanent so that daily RESETTING VPN goes away.
SonicWALL Firmware Version: SonicOS Enhanced 184.108.40.206-117o
Thanks for your help in advance.