Difference between revisions of "Packet Layout"
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==Appended Acks== | ==Appended Acks== | ||
* Bytes n+(data length) thru acks | * Bytes n+(data length) thru acks | ||
** Rest of packet is | ** Rest of packet is filled with as many acks from previous reliable messages as will fit. | ||
See also: [http://www.libsecondlife.org/protocol/index.php/Protocol_%28network%29 libsecondlife documentation] | See also: [http://www.libsecondlife.org/protocol/index.php/Protocol_%28network%29 libsecondlife documentation] | ||
Revision as of 17:16, 28 December 2006
Packet Layout Visualization
+-+-+-+-+-------+---------------+---------------+---------------+ |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
For further explanation of the bits in the header, see Messages and Packet Accounting
Body
- Bytes n thru n+(data length)
- Body of packet
Appended Acks
- Bytes n+(data length) thru acks
- Rest of packet is filled with as many acks from previous reliable messages as will fit.
See also: libsecondlife documentation