What are the last two bits of a DS field in DiffServe Byte used for?

The correct answer is B. ECN. The Differentiated Services (DS) byte in an IP packet header is 8 bits total. The first 6 bits form the DSCP (Differentiated Services Code Point) field used for QoS marking. The remaining last 2 bits are reserved for ECN - Explicit Congestion Notification. ECN allows network devi

Infrastructure and Quality of Service

Question

Options

AAFxy
BECN
CINC
DRMI

How the community answered

(16 responses)

A
6% (1)
B
88% (14)
D
6% (1)

Explanation

The Differentiated Services (DS) byte in an IP packet header is 8 bits total. The first 6 bits form the DSCP (Differentiated Services Code Point) field used for QoS marking. The remaining last 2 bits are reserved for ECN - Explicit Congestion Notification. ECN allows network devices to signal congestion to endpoints without dropping packets, enabling TCP to react before packet loss occurs. AFxy refers to Assured Forwarding DSCP values (which occupy bits within the 6-bit DSCP field), not the last 2 bits. INC and RMI are not standard DS field terms.

Topics

#DiffServ#QoS#ECN#IP Header

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