testD43355
Contents
Testbed: single FreeBSD CURRENT virtual machine(VM) under the FreeBSD/bhyve hypervisor.
Test method: Use the packetdrill scripts provided in D43355, tcpdump and siftr2. The scripts create tun0 so use packetdrill's options to keep the tun0 for tcpdump/siftr2 in a second run, for example packetdrill --tun_dev=tun0 --persistent_tun_dev ${drill_name}
tcpdump captures
The attached two before_fix.pcap and after_fix.pcap are the traces from tcpdump.
netstat
The netstat -sp tcp shows:
before the fix |
52 data packets (52000 bytes) retransmitted |
after the fix |
38 data packets (38000 bytes) retransmitted |
cwnd and ssthresh
The attached two cwnd_chart.png and ssthresh_chart.png shows the congestion window and slow-start threshold before/after the fix.
TCP cwnd before/after fix: 
TCP ssthresh before/after fix: 
The raw data filtered from siftr2 is also attached as cwnd_before_fix.txt and cwnd_after_fix.txt