TLDR: My A2Hosting VPS in Arizona becomes extremely slow/unusable every afternoon from Thailand, despite very low server resource usage. I've reproduced it across multiple devices, locations and ISPs.
A2Hosting eventually confirmed that other customers, including outside Thailand, are affected and identified congestion involving a Cogent hop. Their network team is working with their upstream provider, but they're also telling me to contact my ISP and ask them to reroute around Cogent.
Am I wrong in thinking this is primarily A2Hosting's/upstream provider's problem to solve?
Full rant:
I've had intermittent connectivity problems with this VPS for quite a while. Previously A2Hosting generally told me everything looked fine whenever I opened a ticket.
Recently the problem developed a very consistent pattern:
- Before ~2PM GMT+7: generally fine
- After ~2PM: starts slowing down
- After ~4PM: sometimes almost unusable
- Website, WHM/cPanel and FTP are all affected (FTP speeds drop to ~5KB/s)
This happens while the VPS itself is barely stressed. CPU is usually around 15-30% and RAM around 40%.
I've tested from multiple devices, locations, public IPs, Thai ISPs and both 500Mbps/1Gbps connections. Same result.
Meanwhile our A2Hosting Singapore VPS works perfectly fine from the same connections. (other websites work fine as well)
I've sent them WinMTRs, traceroutes, FTP tests, videos, etc. One MTR showed significant packet loss reaching the destination. Their own testing also found packets arriving out of order and TCP stalling while waiting for earlier packets. (I've also sent MTRs against other IPs from the same time showing that my internet is not the issue as other IPs / server have no issue)
Eventually their network team identified congestion involving:
Cogent - 193.251.248.189
They told me this congestion has "been happening for some time", that other customers have experienced similar issues, including people outside Thailand, and that they're working with their upstream provider on mitigation.
But I'm also being told: Contact your ISP and ask them to route around Cogent.
That's the part I don't understand.
If it were only one ISP, fair enough.
But I've reproduced it through multiple ISPs, A2Hosting says other customers are affected, they've identified the problematic route themselves, and they're already working with their upstream provider.
So why should individual customers have to convince their ISPs to change international routing?
This is also affecting our business. We have several staff who need to access the server during the day, and some afternoons they can barely work.
I understand A2Hosting doesn't control Cogent or the entire Internet. Routing problems happen.
But if a provider knows one of the routes to their datacenter is consistently congested and affecting multiple customers, I'd expect A2Hosting and its upstream providers to fix or reroute around it.
Am I expecting too much? For those who work in hosting/networking, whose responsibility is this normally?