Unable to Connect with WSD Service via Mobile App

[usman_flutter]

## Problem: Detecting HP Printers in Flutter Mobile App

### Issue Description

I'm developing a Flutter mobile application for Android/iOS that needs to automatically discover and connect to HP printers on the same network. Currently, I'm facing challenges with WSD (Web Services on Devices) printer detection.

### Background

- **Target Devices**: Android and iOS mobile phones
- **Use Case**: Auto-discover HP printers connected to WiFi network
- **Current Challenge**: Understanding the best approach to implement printer discovery

### Specific Questions

1. **Native Support vs Manual Implementation**
- On Windows, WSD printer discovery is built-in at OS level
- Does Android/iOS have native WSD support, or does the app need to manually implement it?
- What's the recommended approach for mobile apps?

2. **Available Solutions**
- Should I use the `multicast_dns` package for mDNS-based discovery?
- Is there an official HP SDK for Flutter that handles printer discovery?
- Should I implement WS-Discovery protocol manually using UDP multicast (port 3702)?

3. **Technical Requirements**
- Do I need to install printer drivers in the app?
- What permissions are required on Android/iOS?
- Are there any network/firewall considerations?

4. **HP-Specific**
- Can HP printers be discovered via mDNS or is WSD mandatory?
- Does HP provide any official Flutter/Dart SDK for printer discovery?
- Are there specific HP printer models that support different discovery protocols?

### What I've Tried

- Researched WSD (Web Services on Devices) protocol
- Found `multicast_dns` package but unsure if it works for all HP printer models
- Looked into platform channels (Kotlin/Swift) but want to know if there's a simpler solution

### Expected Outcome

Reliable, cross-platform (Android + iOS) printer discovery that:
- ✅ Automatically finds HP printers on the network
- ✅ Works without additional driver installation
- ✅ Handles both mDNS and WSD protocols
- ✅ Provides clear device information (name, IP, port)

### Environment

- **Framework**: Flutter
- **Target Platforms**: Android 8+, iOS 12+
- **Network**: WiFi (same network as printer)
- **Printer**: HP printers with WSD support

### Code Example (What I'm Trying)

```dart
// Current approach using multicast_dns
import 'package:multicast_dns/multicast_dns.dart';

Future<void> discoverPrinters() async {
final mdns = MDnsClient();
await mdns.startDiscovery('_ipp._tcp.local');

mdns.onServiceAdded?. listen((service) {
print('Printer: ${service.name}');
});
}
```

**Issue**: This only works for mDNS-enabled printers. Not sure if all HP printers support this.

### Additional Context

- I want to avoid platform-specific code if possible
- Need solution that works offline (local network only, no cloud)
- Performance is important - discovery should be fast
- Support for multiple HP printer models would be ideal

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**Please advise on the best approach and if HP has any official resources/SDKs for Flutter development.**