NETWORK LAYER
INTRODUCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Segment Header
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Packet Header
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Frame Header
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Bit
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Detailed explanation-1: -PDU is a significant term related to the initial four layers of the OSI model. In Layer 1, PDU is a bit, in Layer 2 it is a frame, in Layer 3 it is a packet and in Layer 4 it is a segment.
Detailed explanation-2: -Encapsulation of Protocol Data Units Encapsulation or layering is the addition of Protocol Control Information (PCI) to a Protocol Data Unit (PDU) by a communications protocol. The encapsulation adds headers before the start of a PDU.
Detailed explanation-3: -A TCP segment (layer 4 PDU) becomes a layer 3 SDU, which is encapsulated into a layer 3 PDU through the addition of an IP header. This becomes the payload of an Ethernet frame, which is a layer 2 PDU containing an Ethernet header, layer 2 SDU (the IP datagram) and Ethernet footer.