pub const PREAMBLE_ENCODED_SIZE: u32 = 4
    + 4
    + 4
    + 8
    + BURNCHAIN_HEADER_HASH_ENCODED_SIZE
    + 8
    + BURNCHAIN_HEADER_HASH_ENCODED_SIZE
    + 4
    + MESSAGE_SIGNATURE_ENCODED_SIZE
    + 4; // 165u32
Expand description

P2P preamble length (addands correspond to fields above)