Hi,
All was working well until the following day (April 2023) . I suspected M1 did some upgrade on their network. Called their technical support, send them email. But they claimed that no one complain about the issue.
We are using our own software to connect to AWS Postgresql. We tried other ISP like Singtel. It is working fine over Singtel mobile networks. If I tried single connection to AWS, I will not able to see any issues. When I tried multiple connections and disconnections, the problem arises. M1 ISP some how blocks or limit the number of connections to AWS. If M1 and Singtel are routing to the same AWS, I should be able to see the trace route to a single source. Unfortunately, the traceroute tells different story. It seems like M1 using NAT instead.
I hope this information will provide some light to raise awareness about M1 ISP. I do not think that this issue can be resolve soon. At the mean time we will use other ISP as alternative. Good Luck to M1 ISP.
