Tc (command)

wikipedia:Tc (Linux) show and manipulate traffic control settings

• Man page: https://man7.org/linux/man-pages/man8/tc.8.html

To increase round-trip

tc qdisc add dev eth0 root netem delay 5000ms

tc qdisc add dev eth0 root netem loss 10%

netem 
Network Emulator is an enhancement of the Linux traffic control facilities that allow to add delay, packet loss,
             duplication and more other characteristics to packets
             outgoing from a selected network interface.

Related

• PacketShaper
• TeamCity
• iproute2
• tc-netem
• iperf

See also

• Traffic shaping: Network bandwidth, tc, PacketShaper, Traffic QoS, IEEE P802.1p, Netperf
• ip [link, route], ifconfig netstat ss lsof ping ethtool mii-tool arping nmcli(RHEL) route networkctl, netplan, tc

https://netbeez.net/blog/packet-loss-round-trip-time-tcp/