find total amount of network traffic on a particular port
 

I am running some tests and have to measure the total amount of traffic on a port during the duration of the test. Is there any tool or utility on Ubuntu that would let me measure that?

ifconfig will show you the total Rx and Tx bytes for an interface. If you run it before and after your test you should have a good estimate of the traffic your test generated.

iftop may work. (cli)
Check the help (push h once started iftop) but you can configure it to show ports and cumulative usage of each connection (along with its port)

I don't want it displayed on a screen. I would like a command that keep track of the amount of traffic that has passed through the a particular port in a particular time interval so that I could log it in a log file and combine it with my test results.

ethtool ?

or iptraf (does logging)...

is this part of the same assignment ?:
http://www.linuxquestions.org/questi...se-4175544158/

http://serverfault.com/questions/195...ddress-on-port appears to contain a solution