title: Keep SSH session alive
body: <p>I use <code>ssh -p8520 username@remote_host</code> to login remote server.</p>
  
  <p><strong>Issue</strong>:</p>
  
  <p>It is always connected and works properly when I am in the work place. Unfortunately, terminal freezes in 10 - 15 minutes after I connected with the remote server from home. </p>
  
  <p>There's no error/timeout report on the console but the cursor cannot move any more.</p>
  
  <p>When enter <kbd>w</kbd> to check the login users, some zombies login users are there, and I have to kill them manually.</p>
  
  <p>This is quite annoying. Can anyone help me? </p>