The application data field allows the host of an LDN network to encode game-specific information into the advertisement frame. This page describes how the application data is structured in games that use the Pia framework.
The application data starts with a short header, which is followed by game-specific application data.
5.2 - 5.7:
| Offset | Size | Description | 
|---|---|---|
| 0x0 | 4 | Session id (random) | 
| 0x4 | 4 | CRC32 of user password | 
| 0x8 | 1 | System communication version | 
| 0x9 | 3 | Padding | 
| 0xC | 8 | Always 0 | 
| 0x14 | Application data | 
5.9 - 5.18:
| Offset | Size | Description | 
|---|---|---|
| 0x0 | 4 | Session id (random) | 
| 0x4 | 4 | CRC32 of user password | 
| 0x8 | 1 | System communication version | 
| 0x9 | 1 | Header size (24) | 
| 0xA | 2 | Padding | 
| 0xC | 4 | Session param (random) | 
| 0x10 | 8 | Always 0 | 
| 0x18 | Application data | 
5.39:
| Offset | Size | Description | 
|---|---|---|
| 0x0 | 4 | Session id (random) | 
| 0x4 | 4 | CRC32 of user password | 
| 0x8 | 1 | System communication version | 
| 0x9 | 1 | Header size (16) | 
| 0xA | 2 | Padding | 
| 0xC | 4 | Session param (random) | 
| 0x10 | Application data | 
System Communication Version
| Version | Pia Version | 
|---|---|
| 1 | 5.2 - 5.7 | 
| 2 | 5.9 | 
| 3 | 5.10 | 
| 4 | 5.11 - 5.17 | 
| 5 | 5.18 | 
| 8 | 5.39 | 
Application Data
The application data depends on the game:
Mario Kart 8 Deluxe
| Offset | Size | Description | 
|---|---|---|
| 0x0 | 1 | Unknown | 
| 0x1 | 33 | Nickname | 
| 0x22 | 2 | Padding | 
| 0x24 | 88 | Mii info | 
| 0x7C | 4 | Unknown | 
Super Mario Maker 2
| Offset | Size | Description | 
|---|---|---|
| 0x0 | 8 | Network service account id | 
| 0x8 | 11x2 | Nickname (wide chars) | 
| 0x1E | 2 | Padding | 
| 0x20 | 88 | Mii info | 
| 0x78 | 16 | Unknown |