Does Firewall/Router matters when inbound calls does not rings on the cisco SPA303 it only flashes and lit up?
The 3 currents Cisco SPA303 was working with different provider with no problem using a TFTP provisions, I changed from to a new provider because of cheaper price and better tech support and factory reset the phones in order to provision with new provider, the problem that I am having is the phones does not ring when there is an incoming calls, only flashes or beep and it's been doing intermittently, sometimes works sometimes it does not, the new provider claims that my router does not support VOIP and that is why the issue, but what I don't understand if same Firewall/Router was working with old provider why new provider says that is does not work with them.
I need an expert opinion on this, I researched googling and the only possible problem that I could have would be with call drops because of router packets drops.
Can anyone clarify if Firewall/Router is the problem?
Thanks