cspiro
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Is it normal to have many ACKs for a SYN in TCP protocol?
In using Ethereal to capture TCP data for a web browser communicating with a web server, we are seeing a SYN begin and then many ACKs (10-20) before the ACK, FIN. Is this normal?
ASKER
Could the mulitple ACKs occur because the web server is rendering multiple frames as a result of the HTTP submission by the user on the web browser? Or, are multiple ACKs always a sign of lost packets and retransmissions, thus an indication that there is something wrong with the network?
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ASKER
How can I determine from the ethereal report if the ACKs are a result of chopped data vs. a network problem? In this case the full transmission of for the TCP Stream took 1.3 seconds. I'm trying to figure the cause of the delay. I assume that if the answer is 'chopped data' then it's a matter of the amount of information being sent vs. a network problem. Thanks for your assistance.
-> SYN
<- SYNC,ACK
->ACK
(repeat many times
->REQ_DATA
<-ACK
<-REPL_DATA
->ACK
)
->FIN
<-FIN,ACK
->ACK
Since packets may get lost in the new, some messages may be retransmitted multiple times.
Refer http://www.ssfnet.org/Exchange/tcp/Graphics/tcpStateDiagram1.gif