Is TCP over UDP VPN reliable?

Question

Does TCP in applications will be reliable if I will use it over UDP VPN? For example, I have VPN server with some application listen TCP on 10.8.0.1:8080 and I will connect from TCP from host 10.8.0.2 to 10.8.0.1:8080. Will it be reliable?

|----------|   udp tunnel         |----------|
|  Server  |----------------------|  Client  |
| 10.8.0.1==========tcp=============10.8.0.2 |
|          |----------------------|          |
|----------|                      |----------|

Answer 1

TCP is a protocol on top of IP. IP by itself is unreliable, so all the reliability is done at the TCP protocol level. If you use a UDP based VPN it usually encapsulates the IP into UDP, i.e. an unreliable protocol (IP) into another unreliable protocol (UDP). But since the reliability is implemented at the TCP level this does not matter, i.e. TCP over IP over UDP VPN is still a reliable protocol.