pub const BYTE_IAC: u8 = 255; // interpret as command:
pub const BYTE_DONT: u8 = 254; // you are not to use option
pub const BYTE_DO: u8 = 253; // please, you use option
pub const BYTE_WONT: u8 = 252; // I won't use option
pub const BYTE_WILL: u8 = 251; // I will use option
pub const BYTE_SB: u8 = 250; // interpret as subnegotiation
pub const BYTE_SE: u8 = 240; // end sub negotiation