val get_checksum : Cstruct.t -> Cstruct.uint16
val set_checksum : Cstruct.t -> Cstruct.uint16 -> unit
val get_id : Cstruct.t -> Cstruct.uint16
val set_id : Cstruct.t -> Cstruct.uint16 -> unit
val get_seq : Cstruct.t -> Cstruct.uint16 -> unit
val set_seq : Cstruct.t -> Cstruct.uint16 -> unit