Difference between revisions of "Packet Layout"

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Header:
Header:
* Byte 0, most 4 significant bits: Packet Information
* Byte 0, 4 most significant bits: Packet Information
** LL_ACK_FLAG 0x10  
** LL_ACK_FLAG 0x10 -- This packet contains appended acks.
** LL_RESENT_FLAG       0x20  
** LL_RESENT_FLAG 0x20 -- This packet is a resend from the source.
** LL_RELIABLE_FLAG 0x40  
** LL_RELIABLE_FLAG 0x40 -- This packet was sent reliably (implies please ack this packet)
** LL_ZERO_CODE_FLAG   0x80  
** 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.
* 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 14:28, 31 October 2006

Header:

  • Byte 0, 4 most significant bits: Packet Information
    • LL_ACK_FLAG 0x10 -- This packet contains appended acks.
    • LL_RESENT_FLAG 0x20 -- This packet is a resend from the source.
    • LL_RELIABLE_FLAG 0x40 -- This packet was sent reliably (implies please ack this packet)
    • 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.
  • 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