CyberCertPrepNetwork FundamentalsOSI & TCP/IP ModelsEASYFree question
Scenario
A packet capture shows a TCP segment with flags PSH=1 and ACK=1 from the client to the web server. The data payload is 412 bytes.
What does the PSH flag tell the receiving application, and how does it differ from a normal ACK segment?
- A.PSH is equivalent to the TCP URG flag and routes data through the urgent pointer mechanism. The maximum segment size is negotiated during teardown, in the FIN exchange. The application layer in the TCP/IP model handles bit-level line coding such as Manchester encoding. A frame is the Layer 4 protocol data unit produced once TCP finishes segmentation. A baseline is useful only during outages, since normal traffic is self-describing
- B.PSH causes the sender to retransmit all previously unacknowledged segments immediately.
- C.PSH (Push) tells the receiving TCP stack to pass the data to the application immediately rather than buffering it. Without PSH, the OS might wait for the buffer to fill before delivering to the application. ACK alone (no PSH) typically indicates an acknowledgment segment without urgent data delivery pressure; PSH+ACK is used when the sender wants to ensure the application gets the current data without delay.