Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

What is typical TCP ACK response time in a good network? One would think it is in microseconds. We have a situation that is going over 200 milliseconds.


migration rejected from Oct 16 '13 at 12:43

This question came from our site for professional and enthusiast programmers. Votes, comments, and answers are locked due to the question being closed here, but it may be eligible for editing and reopening on the site where it originated.

closed as too broad by kce, Falcon Momot, Ward, Magellan, cole Oct 16 '13 at 12:43

There are either too many possible answers, or good answers would be too long for this format. Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs.If this question can be reworded to fit the rules in the help center, please edit the question.

This very much depends on the characteristics of the network and how busy it is. There is no one size fits all timing statistic for this. – JamieSee Aug 10 '12 at 20:23
Is this LAN? WAN? from where to where? Is it consistent? – Chida Aug 12 '12 at 13:30
Well, lets get logic straight. In order to expect an answer in microseconds the round trip time of a packet has to be less than 50% of that.... so if expectation is below millisecond that means a decent office network - i.e. 1gb switch, not too far, definitly not a campus. A LAN involved likely will take that way above millicesond to start with transmit times, and then microsecond answers would be worth a nobel price for time travel. – TomTom Oct 15 '13 at 22:14

"TCP delayed acknowledgment is a technique used by some implementations of the Transmission Control Protocol in an effort to improve network performance. In essence, several ACK responses may be combined together into a single response, reducing protocol overhead. However, in some circumstances, the technique can reduce application performance."

The Nagle algorithm can have some unusual edge cases that result in delays. If you want to confirm it is due to delayed ack, there is usually an operating system setting to disable the feature. It may be worth noting that on Windows, the delayed ACK timer is 200 ms.

+1 for pointing out the delay may not be related to a network at all, but to protocol configuration features. – TomTom Oct 15 '13 at 22:12