Final Test: Tested with wire Internet connection without any router in-between. This was the only computer connected to the Internet during this test. I think this is Rithmic issue rather than my network or HW. This issue happens about an hour before the market open and disappear about an hour after market open.
Sounds like your ISP's network. US market open in Korean time zone about peak time for evening viewing... video streaming = netflix effect = peak bandwidth usage. Use a VPS!
Finally I resolved my issue myself. It wasn't HW or network issue. The solution is to use Singapore server in every Rithmic platforms I use (I live in S.Korea). I am not sure but it may affect each other. So, for safety, just use this server to everything. Also, wired connection's recommended. Now all platforms except MotiveWave work fine. Only MotiveWave doesn't have an option to select server and it's still lagging. Expect this feature is implemented in the future update release. I am disappointed that Rithmic and other SW vendors couldn't help me with this simple solution.....
I am disappointed you didn't ready any of my previous messages. It's clearly an intermediate network issue. Your ISP has better/non-congested bandwidth to Singapore than USA. Given you didn't test your network connectivity out of your country, the fault is entirely yours. Don't blame others.
Sorry, I cannot waste my time anymore. I need to focus on my trading especially in this busy days. There are many factors to check/test, and my ISP is just repeatedly saying their line is fine. I can try to replace my PC, ISP or router but as everything back to normal, I am not really up to this. Thanks,
As I use Rithmic, I think their affiliate TheOmne.net should be the best choice. Anyway, as I am a manual trader I don't think I need a VPS urgently.