I can definitely notice an improvement in performance when I use a VPN, however it would be cool to see where things are being delayed. Is traceroute or curl something that could help here?
Yea, if it’s faster via VPN that’s a strong hint. If you want proof you need to examine the internet between you and the site. If a VPN connection that uses a specific router to to the site is fast, your connection through that same router is slow, and you can connect to some other site through that same router and get a fast connection, then that’s a smoking gun that your connection is deliberately slowed.
That said, it’s not easy to prove it’s your country/ISP doing the slow down vs that website slowing down connections to your country.
My company has a residential proxy network that lets you test endpoints with requests from residential broadband ISPs all over the world. Some of our customers are using our network for exactly this use case: https://packetstream.io
I ran a curl test and noticed that the TCP connect time is where things are getting hung up, taking over 80 seconds! Does anyone know if this is indicative of deliberate rate limiting or just a bad peering connection?
Possibly neither, that is, there are many possible reasons.
for example, stateful firewalls can only track a certain number of connections. If you don't have a public IP, or if they are trying to protect you, it may be necessary to wait for a connection resource to come available. Connections are generally expensive, different from data transfer, for these and other reasons, such as port starvation, syn flood defenses inappropriately targeting you, so many others.
If it takes 80 seconds to TCP connect, something is pretty wrong.
tcpdump / wireshark would likely show lots of retransmits. Traceroute/mtr may give you an idea of where the loss starts. If you can find servers on similar hosting, you can get some idea of if it's targetted or not.
That said, it’s not easy to prove it’s your country/ISP doing the slow down vs that website slowing down connections to your country.