Data Types

Type	Length	Notes
unsigned char	1	A integer that ranges from 0 to 255
char	1	A integer that ranges from -128 to 127
unsigned short	2	A integer that ranges from 0 to 65535
short	2	A integer that ranges from -32768 to 32767
unsigned triad	3	A integer that ranges from 0 to 16777215
triad	3	A integer that ranges from −8388608 to 8388607
unsigned int	4	A integer that ranges from 0 to 4294967295
int	4	A integer that ranges from -2147483648 to 2147483647
unsigned long	8	A integer that ranges from 0 to 18446744073709551615
long	8	A integer that ranges from -9223372036854775808 to 9223372036854775807
float	4	It's range is 3.4E +/- 38 (7 digits)
double	8	It's range is 1.7E +/- 308 (15 digits)
raknet magic	16	The offline packet identifier of RakNet (00 ff ff 00 fe fe fe fe fd fd fd fd 12 34 56 78)
raknet string	2 + string length	A UTF-8 encoded string with a big endian unsigned short as a prefix to identify its length
raknet address	7	The first byte is the address version (practically always 4). The next 4 bytes are the 4 parts of the IP address and they are decoded by subtracting the part's value from -1 and adding 255 to the result ((-1 - part) + 255). This applies for each byte one by one. The next 2 bytes are the port. They are a big endian unsigned short.
bool	1	Any number that isn't 0 is True. 0 will always be false.

Offline Packets

Unconnected Ping (0x01)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
client timestamp	unsigned long	big endian
magic	raknet magic	N/A
client guid	unsigned long	big endian

Unconnected Ping Open Connections (0x02)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
client timestamp	unsigned long	big endian
magic	raknet magic	N/A
client guid	unsigned long	big endian

The Unconnected Ping Open Connections is only sent when there are open connections in the server.

Unconnected Pong (0x1c)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
client timestamp	unsigned long	big endian
server guid	unsigned long	big endian
magic	raknet magic	N/A
data	raknet string	N/A

This is an example of what you can put in the data field.

MCPE;Dedicated Server;440;1.17.0;0;10;13253860892328930865;Bedrock level;Survival;1;19132;19133;

Incompatible Protocol Version (0x19)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
protocol version	unsigned char	N/A
magic	raknet magic	N/A
server guid	unsigned long	big endian

Open Connection Request 1 (0x05)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
magic	raknet magic	N/A
protocol version	unsigned char	N/A
mtu size	char[]	N/A

The actual mtu size is the size of the char array. The protocol version in the latest version of Minecraft Bedrock Edition is 10. If the protocol version of the client is not the same as the server's the server responds with a Incompatible Protocol Version packet

Open Connection Reply 1 (0x06)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
magic	raknet magic	N/A
server guid	unsigned long	big endian
use security	bool	N/A
mtu size	unsigned short	big endian

Open Connection Request 2 (0x07)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
magic	raknet magic	N/A
server address	raknet address	N/A
mtu size	unsigned short	big endian
client guid	unsigned long	big endian

Open Connection Reply 2 (0x08)

Field name	Field Type	Field Endianess
id	unsigned char	N/A
magic	raknet magic	N/A
server guid	unsigned long	big endian
client address	raknet address	N/A
mtu size	unsigned short	big endian
use encryption	bool	N/A

Acknowledements

Records

A record can either be a single sequence number or a range between 2 sequence numbers (if we have 1 and 8 the numbers will be [1, 2, 3, 4, 5, 6, 7, 8]).

Record Packet Structure

Condition	Field name	Field Type	Field Endianess
N/A	is single	bool	N/A
if is single	sequence number	unsigned triad	little endian
if is not single	sequence number start	unsigned triad	little endian
if is not single	sequence number end	unsigned triad	little endian

Packet Structure

Field name	Field Type	Field Endianess
id	unsigned char	N/A
record count	unsigned short	big endian
records	record[]	N/A

if the packet is used for sending the successfully arrived packets the packet id is 0xc0. if the packet is used for sending the not arrived packets the packet id is 0xa0.

Frame Sets

Reliability Type Table

id	name	is reliable	is sequenced	is ordered
0x00	unreliable
0x01	unreliable sequenced		✔	✔
0x02	reliable	✔
0x03	reliable ordered	✔		✔
0x04	reliable sequenced	✔	✔	✔
0x05	unreliable with ACK receipt
0x06	reliable with ACK receipt	✔
0x07	reliable ordered with ACK receipt	✔		✔

MFDGaming/MinecraftRakNetDocumentation