Reliable Sliding Window

The reliable sliding window ensures that all packets arrive and in the correct order. Large messages are fragmented. The reliable sliding window is used by the following protocols:

• Mesh protocol
• Session protocol
• Reliable protocol
• Broadcast reliable protocol
• Stream broadcast reliable protocol

When a reliable sliding window is used, messages are wrapped as follows:

Up to 5.12:

Offset	Size	Description
0x0	2	Flags
0x2	2	Payload size
0x4	4	Padding
0x8	4	Sequence id
0xC	4	Acknowledgement id
0x10	8	Extra acknowledgements
0x18		Payload

5.14:

Offset	Size	Description
0x0	2	Flags
0x2	2	Payload size
0x4	2	Sequence id
0x6	8	Unknown
0xE	8	Unknown
0x16		Payload

5.17 - 5.19:

Offset	Size	Description
0x0	1	Flags
0x1	1	Stream id
0x2	2	Payload size
0x4	2	Sequence id
0x6	2	Lowest sequence id pending ack
0x8	1	Number of multicast constant ids (N)
0x9	8*N	Multicast constant ids
		Payload

5.31:

Offset	Size	Description
0x0	1	Flags
0x1	1	Stream id
0x2	2	Payload size
0x4	2	Sequence id
0x6	2	Unknown
0x8	1	Unknown
0x9	4*N	Unknown
		Payload

Flags

Flag	Description
1	Has payload
2	First fragment
4	Last fragment
8	Is initialize
16	Is compressed
32	Reset
64	Reset ack