udp-ping-client.go

package main

import (
	"fmt"
	"net"
	"os"
	"sort"
	"time"
)

func main() {
	if len(os.Args) != 3 {
		fmt.Fprintf(os.Stderr, "Usage: %s <host:port> <number_of_packets>\n", os.Args[0])
		os.Exit(1)
	}

	serverAddr := os.Args[1]
	numPackets := 10                          // Default number of packets
	fmt.Sscanf(os.Args[2], "%d", &numPackets) // Parse the desired number of packets from command line

	addr, err := net.ResolveUDPAddr("udp", serverAddr)
	if err != nil {
		fmt.Println("Error resolving UDP address:", err)
		os.Exit(1)
	}

	conn, err := net.DialUDP("udp", nil, addr)
	if err != nil {
		fmt.Println("Error dialing UDP:", err)
		os.Exit(1)
	}
	defer conn.Close()

	// Slice to store latencies and a slice to track jitter between packets
	latencies := make([]time.Duration, 0, numPackets)
	jitters := make([]time.Duration, 0, numPackets-1)

	var lastLatency time.Duration
	for i := 0; i < numPackets; i++ {
		startTime := time.Now()
		_, err = conn.Write([]byte("ping"))
		if err != nil {
			fmt.Println("Error sending data:", err)
			continue
		}

		buffer := make([]byte, 1024)
		conn.SetReadDeadline(time.Now().Add(1 * time.Second)) // 1 second timeout for the echo
		_, _, err = conn.ReadFrom(buffer)
		if err != nil {
			fmt.Println("Error reading from server:", err)
			continue
		}
		endTime := time.Now()

		latency := endTime.Sub(startTime)
		latencies = append(latencies, latency)

		// Calculate and store jitter
		if i > 0 {
			jitter := latency - lastLatency
			if jitter < 0 {
				jitter = -jitter
			}
			jitters = append(jitters, jitter)
		}
		lastLatency = latency

		fmt.Printf("Packet %d RTT: %v\n", i+1, latency)
	}

	// Sort latencies to calculate percentiles
	sort.Slice(latencies, func(i, j int) bool {
		return latencies[i] < latencies[j]
	})

	minLatency := latencies[0]
	maxLatency := latencies[len(latencies)-1]
	p50 := latencies[len(latencies)*50/100]
	p95 := latencies[len(latencies)*95/100]
	p99 := latencies[len(latencies)*99/100]

	// Calculate average jitter
	var totalJitter time.Duration
	for _, jitter := range jitters {
		totalJitter += jitter
	}
	averageJitter := totalJitter / time.Duration(len(jitters))

	fmt.Printf("Min RTT: %v\n", minLatency)
	fmt.Printf("P50 RTT: %v\n", p50)
	fmt.Printf("P95 RTT: %v\n", p95)
	fmt.Printf("P99 RTT: %v\n", p99)
	fmt.Printf("Max RTT: %v\n", maxLatency)
	fmt.Printf("Average Jitter: %v\n", averageJitter)
}