Wireshark-users: Re: [Wireshark-users] Question about ACK number
Date Index · Thread Index · Other Months · All Mailing Lists
Date Prev · Date Next · Thread Prev · Thread Next
From: Sake Blok <sake@xxxxxxxxxx>
Date: Mon, 15 Apr 2013 09:25:09 +0200
Hello Amit,

Yes, this is normal. Before the data stream and after the data stream, there is 1 phantom byte. So the first data packets has a sequence number that is 1 higher than the initial sequence number and after the FIN, there is also one phantom byte. This makes it possible to make a certain that the FIN was seen and not just the last data byte.


Cheers,
Sake


On 15 apr 2013, at 09:10, Amit Aggarwal wrote:

Hello,
 
Please help to comment about ACK calculation in below scenario.
 
Frame100: Client ACKs the data received till now..  ACK= 10000
 
Frame 101:  Server sends client TCP Data ( 924 bytes) with FIN,PSH and ACK flags set.
 
Frame 102: Client sends ACK= 10925    à QUESTION ..Why is client sending 10925 and not 10924 .. Is it adding 1 for FIN received in Frame 101 ..?  Is it normal ?
 
Frame 103:  Client sends FIN,ACK == ACK = 10925
 
Best Regards
Amit
 
___________________________________________________________________________
Sent via:    Wireshark-users mailing list <wireshark-users@xxxxxxxxxxxxx>
Archives:    http://www.wireshark.org/lists/wireshark-users
Unsubscribe: https://wireshark.org/mailman/options/wireshark-users
            mailto:wireshark-users-request@xxxxxxxxxxxxx?subject=unsubscribe