In this figure, the datagram is illustrated as a long blue rectangle divided into segments. From left to right, those segments are: New IP header, ESP header, Original IP header, Original IP datagram payload (the largest segment of the datagram), ESP trailer, and ESP MAC. The ESP header is shaded dark blue, and an expanded view of this segment reveals two segments within it: SPI, and Seq #. The ESP trailer also includes an expanded view with three segments: Padding, Pad length, and Next header. The section of the datagram from ESP header to ESP trailer is identified as "'Enchilada' authenticated," and the section between Original IP header and ESP trailer is identified as "Encrypted."