After 25 years in the industry, I now teach students about areas in IT, including Python, Databases, Robotics and networking. Prior to this, I have worked mainly in Unix/Linux system admin. Started as a C programmer in the late 90's (and still do quite a bit of C programming). I have worked for Vodafone, HP and IBM as a system engineer. Also have knowledge of Storage kit (EMC, HDS and IBM) and Fiber Channel switches (Cisco, Brocade and McData).
Scott Reeves demonstrates the flow graph feature of the Wireshark tool, which can help you check connections between client server, finding timeouts, re-transmitted frames, or dropped connections.
Scott Reeves demonstrates the use of iperf, which provides basic information on throughput, packet loss, and jitter to help you troubleshoot UDP and TCP issues.