[мысли][реально ли?] отправка пакета в уже установленной tcp сессии

Description: The network packet altering stream editor
 NetSED is small and handful utility designed to alter the contents of
 packets forwarded thru your network in real time. It is really useful
 for network hackers in following applications:
 .
   * black-box protocol auditing - whenever there are two or more
     proprietary boxes communicating over undocumented protocol (by
     enforcing  changes in ongoing transmissions, you will be able to
     test if tested application is secure),
 .
   * fuzz-alike experiments, integrity tests - whenever you want to test
     stability of the application and see how it ensures data integrity,
 .
   * other common applications - fooling other people, content filtering,
     etc etc - choose whatever you want to.
 .
 It perfectly fits ngrep, netcat and tcpdump tools suite.