Protocol: ISO 10030 / CONS ES-IS
PDU Part: Fixed Part
Field: network-layer protocol ID
Length: 1 byte
Contents: protocol identificationn on network layer 3.
ISO 10030 = '10001010'.
ISO protocols use the following codes to identify network protocols:
10000001 = ISO 8473 - CLNP
10000010 = ISO 9542 - CLNS ES-IS
10001010 = ISO 10030 - CONS ES-IS
CONS ES-IS is mostly conveyed via X.25.