> I am looking the Tcp Stream Graphs and I see this "Seuence Number[B] either on the X-axus or on the y-axis. The number indicated on the given axes has no connection to the "No." field in the capture window. For example on the graph I am looking at right now, "Round Trip Time Graph" the Sequence Number[B] is 45,000 mag and the number of packets captured are 540,000. So, what is this Sequence Number[B] and how should I interpret it ? I looked the online manual but found nothing regarding this.
The sequence numbers are part of the TCP protocol. Together with the acknowledgement numbers they provide a way of reliable data transport. You are indeed correct that they have no relation to the "No." field.
Using a tool like wireshark is all about understanding the workings of the protocols it is displaying. For each protocol you are investigating, take some time to read how the protocol should work. The RFC's[1] are a great source, but sometimes maybe a little bit to deep for the first encounter. So have a search on google for the protocol name and something like "tutorial". Looking at actual packets while studying the theoretics is the best way to get yourself familiarized with the protocols you need to understand when solving problems.
Hope this helps,
Cheers,
Sake
[1] http://www.ietf.org/rfc.html , the RFC for TCP is 793
