Based on the provided information, the term "push ACK" isn't a standard or directly defined term in networking. However, we can infer its meaning based on the individual components: the PUSH flag and the ACK flag within the context of TCP communication. Therefore, a "push ACK" would likely refer to a TCP segment that has both the PUSH and ACK flags set.
Here's a breakdown:
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ACK (Acknowledgment) Flag: This flag, when set in a TCP segment, indicates that the sender is acknowledging the receipt of data from the other party. It essentially confirms that the data sent earlier has been successfully received.
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PUSH (Push) Flag: According to the provided reference, the PUSH flag suggests to the receiving end that it should process the data in the packet immediately. It signals that the data should be delivered to the application layer as soon as possible, bypassing any buffering that might normally occur. The reference mentions "or it can force the server to process the information in the packet by setting the PUSH flag".
Understanding the Combined Effect: PUSH and ACK
When both the PUSH and ACK flags are set in a TCP segment (hypothetically a "push ACK"), it signifies a combined action:
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Acknowledgment of Received Data: The ACK flag confirms that the sender has successfully received data from the receiver.
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Request for Immediate Processing: The PUSH flag requests the receiver to process the data in that very segment immediately and deliver it to the application.
In essence, a "push ACK" segment is acknowledging previously received data and simultaneously urging the receiver to process the data within that segment without delay.
Hypothetical Scenario
Imagine a client sending a command to a server and expecting an immediate response.
- The client sends data with both the PUSH and ACK flags set.
- The ACK acknowledges the previous data it received from the server (e.g., a previous acknowledgment or part of the server's response).
- The PUSH flag tells the server to process this command data immediately.
This would instruct the server to process this new command (contained within the segment with the PUSH flag) urgently while also acknowledging previous communication.
