What value is assigned to the Diffserv field of an IP packet header to prioritize it?

• A. Differentiated Services Code Point (DSCP) value
• B. DSCP Flag
• C. Diffserv Index
• D. Direct Value

Answer: (A)

Prioritization in IP networks is achieved by setting a Differentiated Services Code Point within the Differentiated Services field of the IP header. That code point, known as the DSCP value, is what routers use to decide how to treat the packet—how fast to forward it, whether to queue it with higher or lower priority, and what PHB (Per-Hop Behavior) to apply. The DSCP value is a 6-bit code that defines the class of service, while the remaining 2 bits in the field are used for ECN (Congestion Experienced) and are not about priority. Terms like a DSCP flag, a diffserv index, or a direct value aren’t standard ways to label the priority mechanism; the precise, standardized element to assign is the DSCP value.