Why can the loading of static files on the site slow down for some clients from the Russian Federation?

Question

Amazon Web Services

There is a simple web application and many clients from the Russian Federation began to complain about such a symptom.
On the server (aws) we have nginx, everything is fine with it, there are no errors in the logs.

This also happens to us, but very rarely. And what could be the matter is not clear.
According to the picture, it is the file download that slows down. Tell me which way to dig.

Answer 1

Of course, you live without CDN (Cloudfront) and without S3?)

Answer 2

Because of the students. Online lessons. At providers, channels up to M9 or (whatever is large now as a central node) are clogged with traffic.
If the channels are wide, then the bottleneck is the watchman from Roskomnadzor (deep traffic analysis). Now there are almost no pure APIs left, which are missed without analysis why the client specifically goes to this site. If Provo does not have DPI, then 50-60% of links simply do not open. A specific page is banned and the point provider does not allow all ip.

Answer 3

Do not forget about network routing (non-optimal routes) and limited bandwidth in conditions of increased use of Internet channels in self-isolation.
Routing.
You are using a static entry point in AWS that lands at a specific physical point on the network. And which, by the way, is definitely not in Russia.
The problem is observed on specific clients -> most likely the route from the client to your server is the problem
Possible solutions
1.CDN (and yes, both AWS and CloudFlare have been recommending driving dynamics through CDN for a long time, there are a lot of guides) - traffic will be sent from the nearest point available to the client (again, depending on the routing settings of a particular provider to the CDN service - they can still problems arise)
2.AWS Global Accelerator - basically the same thing for you. Traffic is routed to the closest GA POP to the client and takes the shortest path inside AWS to your server. But there were no entry points in Russia back in August. Now I do not know.
3. Raise the entry point on the territory of the Russian Federation and transfer traffic to your service in AWS in the tunnel (such a solution, for example, on our project gave the greatest acceleration, neither GA nor CloudFront are comparable, because there we generally do not control traffic routes towards servers AWS)
From the above, either a CDN with points of presence in the Russian Federation or your own point of presence on the servers of the Russian Federation can help you from the above in case traffic from clients goes along a non-optimal route.
Overloaded networks
If the problem is in overloaded networks (the most likely cause now), then nothing will help you.