Difference between revisions of "Packet Layout"
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Rob Linden (talk | contribs) |
Rob Linden (talk | contribs) |
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+-+-+-+-+-------+---------------+---------------+---------------+ | +-+-+-+-+-------+---------------+---------------+---------------+ | ||
|Z|R|R|A| | | |Z|R|R|A| | | ||
| Line 10: | Line 9: | ||
Header: | Header: | ||
* Byte 0, 4 most significant bits: Packet Information | * Byte 0, 4 most significant bits: Packet Information | ||
** LL_ZERO_CODE_FLAG 0x80 -- Packet data is run length encoded, such that series of 1 to 255 zero bytes are encoded to take 2 bytes. | |||
** LL_RELIABLE_FLAG 0x40 -- This packet was sent reliably (implies please ack this packet) | |||
** LL_RESENT_FLAG 0x20 -- This packet is a resend from the source. | |||
** LL_ACK_FLAG 0x10 -- This packet contains appended acks. | ** LL_ACK_FLAG 0x10 -- This packet contains appended acks. | ||
* Bytes 0, (4 least significant bits) to byte 3: (for a total of 28 bit) Packet ID, assigned by circuit | * Bytes 0, (4 least significant bits) to byte 3: (for a total of 28 bit) Packet ID, assigned by circuit | ||
* Everything beyond this is potentially zerocoded for compression | * Everything beyond this is potentially zerocoded for compression | ||
Revision as of 13:53, 31 October 2006
+-+-+-+-+-------+---------------+---------------+---------------+ |Z|R|R|A| | |E|E|E|C| Packet ID (28 bits) | |R|L|S|K| | +-+-+-+-+-------+---------------+---------------+---------------+ | | : :
Header:
- Byte 0, 4 most significant bits: Packet Information
- LL_ZERO_CODE_FLAG 0x80 -- Packet data is run length encoded, such that series of 1 to 255 zero bytes are encoded to take 2 bytes.
- LL_RELIABLE_FLAG 0x40 -- This packet was sent reliably (implies please ack this packet)
- LL_RESENT_FLAG 0x20 -- This packet is a resend from the source.
- LL_ACK_FLAG 0x10 -- This packet contains appended acks.
- Bytes 0, (4 least significant bits) to byte 3: (for a total of 28 bit) Packet ID, assigned by circuit
- Everything beyond this is potentially zerocoded for compression
- Bytes n thru n+(frequency size)
- 1/2/4 byte ID of the message the packet contains
- Bytes n thru n+(data length)
- Body of packet, possibly zero coded.
- Bytes n+(data length) thru acks
- Rest of packet is fill with as many acks as will fit from reliable messages