Reliability between TCPonly and UDP for tinc?

[hvjunk]

The only time I can think off, that you’ll *want* to use TCP, is when UDP doesn’t work through the firewalls/NATting.

> On 18 Jun 2017, at 14:53 , Bright Zhao <startryst at gmail.com> wrote:
> 
> If the concern is more about the reliability instead of throughput, should I add TCPonly = yes in the host configuration to make the VPN runs on TCP?

The problem with TCP, is that TCP, encapsulated inside a TCP stream, is a recipe for very poor performance, as you could have retransmits, encapsulated in retransmits. 

But then the questions might be more like: Have you read up about why VPNs over TCP isn’t a good idea?
And since you have, what reliability issues are you having with tinc over UDP?
And if you have those reliability problems over UDP, what tests have you done to confirm it’s not the network, but the UDP that is less reliable than the TCP VPN settings?