Add TCP traffic measurements

[praveingk]

Included TCP measurements

[praveingk]

Basically, I send 100B packets (by controlling mtu of the interface) and run 128 parallel iperf3s. The traffic runs for 60 sec, and I monitor the throughput, overall packets sent, packets monitered by the agent, cpu ,etc:

• Without any agent, the overall packet rate reaches ~11 Mpps
• With V1 agent, the packet rate drops to 3.7 Mpps, however with V2 it reaches 10.4 Mpps
• With pmacct its about 3.5 Mpps, and tcpdump is about 7.25 Mpps
• The monitoring rate for V2 agent is 100%, but it's much lower for others
• The additional CPU overhead for V2 agent incurred is about 4%, but is much higher for others