A containerized .NET application that measures network latency and performance metrics for any given URL.

This tool provides detailed network performance analysis including:

• DNS lookup times (with averaging capability)
• TCP connection establishment
• TLS/SSL handshake timing
• HTTP Time to First Byte (TTFB)
• Content transfer speed
• Download throughput

# Navigate to the project directory
cd latency-check/LatencyChecker

# Build with Docker
export DOCKER_BUILDKIT=1
docker build -t latency-checker .

# Navigate to the project directory
cd latency-check/LatencyChecker

# Build with Podman
podman build -t latency-checker .

# Check latency for a website (single DNS lookup)
podman run --rm latency-checker https://google.com

# Using Docker
docker run --rm latency-checker https://google.com

# Check latency with multiple DNS attempts for better accuracy
podman run --rm latency-checker https://google.com 100

# Check different websites
podman run --rm latency-checker https://github.com 50
podman run --rm latency-checker https://stackoverflow.com 1000

# Check specific ports
podman run --rm latency-checker https://example.com:8080 10

• URL (required): The target URL to test (must include protocol: http:// or https://)
• DNS_ATTEMPTS (optional): Number of DNS lookups to perform for averaging (default: 1)

Checking latency for https://google.com with 1000 DNS attempts...

+--------------------------------------------------+----------------------+
| Metric                                           | Value                |
+--------------------------------------------------+----------------------+
| DNS Lookup (avg) for 1000 attempts             | 0.41 ms              |
| DNS Lookup (latest)                             | 0.41 ms              |
| TCP Connection                                   | 37 ms                |
| TLS Handshake                                    | 155 ms               |
| Pre-transfer                                     | 192 ms               |
| Redirect Time                                    | 0 ms                 |
| Time to First Byte (TTFB)                       | 382 ms               |
| Content Transfer                                 | 120 ms               |
+--------------------------------------------------+----------------------+
| Total Connection Time (no DNS)                  | 696 ms               |
| Total Time (with latest DNS)                    | 697 ms               |
+--------------------------------------------------+----------------------+
| Download Speed                                   | 1836377 B/s          |
| Content Size                                     | 220548 bytes         |
| Upload Speed                                     | 0 B/s                |
| Remote Address                                   | 142.251.209.14:443   |
| Local Address                                    | 10.88.0.8:34382      |
+--------------------------------------------------+----------------------+

Status Code: 200 OK
Latency check completed.

• DNS Lookup (avg): Average DNS resolution time across all attempts
• DNS Lookup (latest): DNS resolution time for the final lookup used for connection

• TCP Connection: Time to establish TCP connection
• TLS Handshake: Time to complete SSL/TLS handshake (HTTPS only)
• Pre-transfer: Combined TCP + TLS time

• Time to First Byte (TTFB): Time from HTTP request to first response byte
• Content Transfer: Time to download the full response body
• Download Speed: Average download throughput in bytes per second

• Total Connection Time (no DNS): Pure network latency excluding DNS overhead
• Total Time (with latest DNS): End-to-end time including realistic DNS lookup

• Remote Address: Server IP and port
• Local Address: Your local IP and port
• Content Size: Size of downloaded content in bytes
• Status Code: HTTP response status

# Monitor website performance over time
podman run --rm latency-checker https://yourapp.com 100

# Compare different CDN endpoints
podman run --rm latency-checker https://cdn1.example.com 50
podman run --rm latency-checker https://cdn2.example.com 50

# Test DNS performance with high accuracy
podman run --rm latency-checker https://example.com 10000

# Quick DNS check
podman run --rm latency-checker https://example.com 1

# Diagnose slow website loading
podman run --rm latency-checker https://slow-site.com 10

# Check if issues are DNS, TCP, TLS, or server-related
podman run --rm latency-checker https://problematic-site.com 100

• Docker, Podman for building/running
• Network connectivity to target URLs
• Supports both HTTP and HTTPS URLs

• The tool performs two separate connections: one for measuring TCP/TLS timing, and another for HTTP request timing
• DNS attempts parameter helps average out DNS caching effects for more accurate measurements
• Total times exclude DNS measurement overhead but include realistic DNS lookup time
• All times are measured using high-precision system timers

# Ensure BuildKit is enabled for Docker
export DOCKER_BUILDKIT=1


### Runtime Issues
```bash
# For network connectivity issues
podman run --rm latency-checker https://google.com 1

# Check if URL is reachable
curl -I https://your-target-url.com