What part of a packet radio frame contains the routing and handling information?

In packet radio, data is transmitted in discrete blocks called "frames." Each frame is divided into specific sections that serve different structural purposes within the communications network. The "header" is the section positioned at the beginning of the packet frame that contains all the routing and handling information. This includes the callsigns of both the originating and destination stations, as well as the callsigns of any digipeaters the packet must pass through to reach its target. The other sections serve different roles: the "preamble" helps synchronize the receiving station's clock before the data arrives, and the "trailer" typically contains an error-checking mechanism like a Frame Check Sequence (FCS) to verify data integrity. A "directory" is not a standard component of a packet radio frame.