Segment Lost and Dup Ack Happen Frequently


Hi All Expert,

I’m new in using wireshark for troubleshooting my network, I was start capture my network since when our network connection that happen very slow performance. Our server is hosted at Japan and clients access via WAN link. I need help on what I’d capture but not really can understand what is the message wireshark shown. Below my network details,

Server IP = (Hosted Web Application via port 7777)
Client IP =

Below is my screen capture,

Appreciate anyone can guide me what the capture show, segment lost and Dup Ack.
Thank you.