title: How to get process or port Network bandwidth usage in linux
body: <p>I want to get network bandwidth usage for each process. I have found a lot of information about this, such as iftop, <a href="http://nethogs.sourceforge.net/" rel="nofollow">nethogs</a>, <a href="http://sourceforge.net/projects/procexp/" rel="nofollow">linux process explorer</a>...
  But all of them get process brandwidth usage by capture packet(libpcap), by my test in linux it consume a lot of cpu(%10-%15) and the speed of flow is 11MByte/s. If I can get flow rate for each port I can solve this questions because I hava get the table about process port used. So I want to know is there any other way to get port flow without capture packet.</p>