A network workstation initiates an NTP time synchronization request to an external time server. Arrange the outbound protocol data unit (PDU) encapsulation steps in the correct order, starting from the application data generation down to physical transmission.
- 1The NTP payload is passed to the transport layer, where a UDP header containing port 123 is appended to form a segment.
- 2The segment is passed to the network layer, where an IP header containing source and destination IP addresses is prefixed to form a packet.
- 3The packet is delivered to the data link layer, where an Ethernet header with MAC addresses and an FCS trailer are attached to construct a frame.
- 4The frame is encoded into electrical signals or light pulses for transmission across the physical medium.
Answer
The correct sequence starts with creating a Layer 4 UDP segment, encapsulating it into a Layer 3 IP packet, wrapping it in a Layer 2 Ethernet frame with an FCS trailer, and finally converting the frame into Layer 1 physical signals.
During outbound network transmission, data moves down the protocol stack. The Application data is first encapsulated with a Transport layer (Layer 4) UDP header to form a Segment. Next, the Network layer (Layer 3) adds an IP header to create a Packet. Then, the Data Link layer (Layer 2) appends an Ethernet header and FCS trailer to create a Frame. Finally, the Physical layer (Layer 1) serializes the Frame into signals across the physical medium.
Step-by-Step Solution
Key Concept
Outbound OSI Encapsulation Sequence (Data -> Segment -> Packet -> Frame -> Bits)
Estimated Time:2m 0s