Labels:text | screenshot | font OCR: AUTHENTICATION HEADER Next headers "Payload Jebetty Reserved Securty parameters index Sequence number; Authentication date Figure 1. The Authentication Header (AH) resides between the IP header and the Encapsulating Security Payload (ESP) or other higher-level protocols, such as UDP or TOP. The chief goal of the All is to let the sending and receiving parties know that the data came from where it says'it did, and that it was fot changed during transit.