ISP blocking the VOIP traffic

[Choicecloud]

Hello,

I just like to get experience from other providers, we have  situations whereby certain providers in the UK like Three Networks, EE and Sky ISP  are blocking VOIP traffic. we opened support ticket with Vodia changing the SIP ports from the default but that has not resolved the issues . The main issue is when we connected either on Apps/Voip handset we have one-way audio.  When we install VPN , the service start working.

But we like to avoid users downloading VPN software just to use the service . We will appreciate if you can share your experience and best practice.  Thanks.

[Vodia PBX]

One way to solve this problem is to use TLS. Then the ISP will have problems determining what is going on. If they still block UDP/RTP other services like WhatsApp will also not work and their support department must be either very busy or very ignorant. 

[Choicecloud]

We have tried using Tls it was the same issues.  Anyway, we are using VPN as a work around.