In the TCP/IP model, exactly one protocol data unit (PDU) in layer N is encapsulated in a PDU at layer N-1. It is possible to group multiple N-level PDUs into one (N-1)-level PDU (blocking). In the case of blocking, is it necessary that each N-level PDU retain its own header or can the data be consolidated into a single N-level PDU with a single N-level header?

Python. primary u.s. interstate highways are numbered 1-99. odd numbers (like the 5 or 95) go north/south, and evens (like the 10 or 90) go east/west. auxiliary highways are numbered 100-999, and service the primary highway indicated by the rightmost two digits. thus, the 405 services the 5, and the 290 services the 90. given a highway number, indicate whether it is a primary or auxiliary highway. if auxiliary, indicate what primary highway it serves. also indicate if the (primary) highway runs north/south or east/west.