UDP 500/4500 must opened on firewall for mobile VPN?

[cn2world]

Hi everyone,

I am reading the following, I quote:

"If your SoftEther VPN Server is behind the NAT or firewall, you have to expose the UDP port 500 and 4500. On the NAT, UDP 500 and 4500 should be transferred to the VPN Server. If any packet filters or firewalls are existing, open UDP 500 and 4500 ports."

But the reality is UDP Port 500 is simply blocked by many ISP, if UDP port 500 is blocked by ISP, there is no way to get Mobile VPN(L2TP) to work?

If it is the case, mobile VPN can still be very easily restricted in many countries, hope someone can get me an answer for this. Thahnks

[cn2world]

My point is if we cannot use HTTPS/443 for mobile VPN, then everything will be useless, as I mentioned earlier, ISP will simply block UDP 500

[inten]

That is why SoftEther has its own client and a protocol.