This protocol is used for the P2P monitoring server on the Switch. The messages are wrapped in unencrypted Pia packets and sent to g<game server id>-%.p.srv.nintendo.net through UDP port 34343.

Wii U games send the monitoring data to the NEX server instead, through the SendReport method of the secure connection protocol.

The message payload is encoded as follows:

Up to 5.6:

5.7 and later:

The content of the payload depends on the version number and data type in the monitoring data header.

The key is chosen by the lower nybble of the encryption key id in the monitoring data header:

 0: c1d494af4a0a956c545d2e41fc1ceb24
 1: caf247fb40aa9655e58c2b02bff89e14
 2: bc6da24db8c7e22d2e3fdd97a2b5e3d2
 3: 3ef3a41d8a2e78518974679562afe5fa
 4: c0a02f90a2642ea6a64b199e01f46a57
 5: 9eb9c98fc889495c7056f2cd8015aac0
 6: 632acbe8c6c77246475b577b6b2d8c76
 7: 8dafd0578b2d3ff285e0292ce08d25a2
 8: cc082ad011d3c38c7b5ed28637f37c1c
 9: 6cd46046c71362116e36cb96c0098912
10: 54598618dc2a24474a9d5e80f783a145
11: f35eaa5cc8ebc1dc42ada6c3f4130556
12: 127d237973e98688548b5dac5eb6cc7b
13: f677ccf32241122aeeece3df23aaa736
14: d7cb0683d251030fc7613b4b2461224b
15: c587a79cbac8a2ddcee27409242a8702

The nonce is constructed as follows:

Monitoring was added to Pia in version 3.4.

As described above, the message payload starts with a monitoring data header. Each monitoring data structure starts with a monitoring data header as well. The flags field is always 0xFC in the first monitoring data header, and 0xFF in all other monitoring data headers.

In the first monitoring data header, the payload size indicates the size of the compressed payload. In all other monitoring data headers, the payload size indicates the size of the structure, including the monitoring data header itself.

Up to 5.6:

5.7 and later:

This part is only relevant in the first monitoring data header. In all other monitoring data headers, it is filled with 0xFF.

All fields are initialized to 0xFF.

Version 18: