TCP Ping

A simple tool for test latency between TCP client/server.

It sends SYN to server and waits for SYN/ACK, then measure RTTs between SYN and SYN/ACK.

Usage

For mac and linux user, you can download executable binary from release page.

If you cannot run these exes, you can clone this repo and build with cargo build (nightly rust environment is required)

$ ./tcpping --help
tcpping 0.1.0

USAGE:
    tcpping [OPTIONS] --if-name <IF_NAME> --hostname <HOSTNAME>

OPTIONS:
    -c, --count <COUNT>          Number of times to ping [default: 10]
    -h, --hostname <HOSTNAME>    Destination hostname(domain or ipv4 address, ipv6 is not tested)
        --help                   Print help information
    -i, --if-name <IF_NAME>      Local interface
    -p, --port <PORT>            Destination port [default: 80]
    -V, --version                Print version information

For example, test latency from my laptop to bilibili.com(47.103.24.173)'s 443 port:

$ ./tcpping -i en0 -h 47.103.24.173 -p 443
SYN&ACK(0) from 47.103.24.173 time=26573 us
SYN&ACK(1) from 47.103.24.173 time=18944 us
SYN&ACK(2) from 47.103.24.173 time=15782 us
SYN&ACK(3) from 47.103.24.173 time=28188 us
SYN&ACK(4) from 47.103.24.173 time=17065 us
SYN&ACK(5) from 47.103.24.173 time=15830 us
SYN&ACK(6) from 47.103.24.173 time=27376 us
SYN&ACK(7) from 47.103.24.173 time=25173 us
SYN&ACK(8) from 47.103.24.173 time=79112 us
SYN&ACK(9) from 47.103.24.173 time=55702 us
Valid Result Count: 10
RTTs(us): 26573.354, 18944.521, 15782.49, 28188.198, 17065.896, 15830.354, 27376.864, 25173.698, 79112.698, 55702.5
AVG RTT(us): 30975.0573

In another example, I want to test a lot of ips and ports' latencies, so I wrote a python script to invoke this tester, and collect results as csv:

import subprocess
import pandas as pd
from tqdm import tqdm
import sys
import itertools
# invoke test command with subprocess and returns avg rtt
assert len(sys.argv) >= 2
ofname = sys.argv[1]


def get_rtt(ip, port=443, device='eth0', iter_cnt=1):
    result = subprocess.run(
        ['tcpping', "-i", device, "-h", ip, "-p", str(port), "-c", str(iter_cnt)], capture_output=True)
    output = result.stdout.decode()
    for line in output.split('\n'):
        if "AVG RTT(us)" in line:
            return float(line.split(" ")[-1])
    return float("nan")


def ip_port_to_str(ip_port):
    ip, port = ip_port
    return ip + ":" + str(port)


if __name__ == '__main__':
    with open('iplist.txt', 'r') as f:
        iplist = [l.strip() for l in f.readlines()]
    testcases = list(itertools.product(iplist, (9443, 443)))
    results = {ip_port_to_str(case): [] for case in testcases}

    # test N times for each ip
    for _ in tqdm(range(10)):
        for case in tqdm(testcases, leave=False):
            ip, port = case
            results[ip_port_to_str(case)].append(
                get_rtt(ip, port))

    df = pd.DataFrame(results)
    df.to_csv(ofname)

And the rtts.csv will looks like:

	a.b.c.d:443	a.b.c.d:9443	a.b.c.d:443
0	74040.4	794195.2	846794.8
1	69776.8	794098.6	861836.2
2	114034.8	795507.2	895464.0
3	80859.0	788424.0	840448.8
4	318998.0	807142.0	852057.8
5	70777.2	802743.6	860137.2
6	87206.4	791429.0	857431.6
7	80243.4	786114.6	851218.8
8	79406.4	804203.4	853117.8
9	79587.8	799656.6	846450.6