Nord vpn offers obfuscated Servers , they say:
Obfuscated servers are specialized VPN servers that hide the fact that you’re using a VPN to reroute your traffic. They allow users to connect to a VPN even in heavily restrictive environments.
When you connect to a regular VPN server, your ISP can’t see where you go online. But it knows that you’re using a VPN from the way your data looks. However, if you connect to an obfuscated server, it changes your data packets. Therefore, tools that are meant to block VPN traffic let it pass. No one notices you’re using a VPN, unless they inspect your data packets manually.
Obfuscated servers are used to bypass VPN-blocking firewalls. To do that, a VPN provider must remove all information related to a VPN from your data so that it looks like regular data packets.
VPN providers can obfuscate data in a few different ways. For example, data packets can be hidden using additional SSL/SSH encryption so that all the VPN metadata is out of sight. Think of it as encryption to conceal your encryption.
Data can also be scrambled, hiding the metadata from the packet header. This way, it looks like regular HTTPS traffic filled with meaningless information. Firewalls can’t recognize it, so they let it pass.
Some internal networks, ISPs, and even countries might ban VPN usage. Obfuscated servers will help you bypass these restrictions. Once you connect, firewalls and VPN blocks won’t be able to recognize that your traffic is coming from a VPN server.
https://nordvpn.com/features/obfuscated-servers/
Is bitdefender currently using this technique ?