Packet Header
=============

With the proposed protocol negotiation described above, the messages received from the UDT socket can now be encoded/decoded as:

- **Flags** *(1 byte / 8 bits)* **:** Describes how to process the rest of the packet
    - **Bits 6-7:** Obfuscation (if non-zero then all following bytes are XORed with the key)
        * 00 - no obfuscation
        * 01 - 0x6362726973736574
        * 10 - 0x7362697261726461
        * 11 - 0x72687566666d616e
    - **Bit 5:** L - Is set if the packet contains a Local Node ID
    - **Bit 4:** V - Is set if the packet contains an MD5 Verification
- **Local Node ID** *(2 bytes / 16 bits little-endian)* **:** If the "L" bit is set in the flags, the Local Node ID represents the node this was sent from
- **MD5 Verification** *(16 bytes)* **:** If the "V" bit is set in the flags, the Verification represents a hash of the remains of the packet as well as a value specific to the node
- **Contents**: A collection of SDXF elements, the outermost field of which describes the Packet Type being used for each

.. note:: I'm increasingly uncertain of the purpose of the "Local Node ID" field and may move to dropping it from all packets