This is our old Q&A Site. Please post any new questions and answers at

When looking at the conversation in .pcap I can see "Calculated window size" is constantly growing with each packet. However there is no Window Update message is sent. Is this normal not to see it?


asked 27 Nov '16, 04:46

emagidso's gravatar image

accept rate: 0%

edited 27 Nov '16, 04:58

Jasper's gravatar image

Jasper ♦♦

Can you claridy? "there is Window update message" - looks like you forgot the "no"? Otherwise the last sentence makes no sense.

(27 Nov '16, 04:56) Jasper ♦♦


Yes I made a typo. "However there is no Window Update message is sent" is the correct one.

(27 Nov '16, 04:57) emagidso

Okay, I updated the question.

(27 Nov '16, 04:59) Jasper ♦♦

"Window Update" only happens if the receiver ACKnowledges something that has already been acknowledged but the window size value has changed. So if you're seeing growing windows while new incoming data is acknowledged it's not a window update.

permanent link

answered 27 Nov '16, 05:01

Jasper's gravatar image

Jasper ♦♦
accept rate: 18%

Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text]( "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 27 Nov '16, 04:46

question was seen: 863 times

last updated: 27 Nov '16, 05:01

p​o​w​e​r​e​d by O​S​Q​A