字节填充图例 FLAG Header Payload field Trailer FLAG Oniginal characters After stuff Ing A FLAG B A ESC FLAG B AESC B A ESC B AESCFLAGB A ESCESCESC FLAG B ESCESC B A ESC ESC ESCESC B (b) (a)aframe delimited by flag bytes (b) Four examples of byte sequences before and after stuffing字节填充图例 (a) A frame delimited by flag bytes (b) Four examples of byte sequences before and after stuffing