title: How long is an open, secure, TCP channel secure?
body: <p>We have a web service that acts as a gateway between our clients and another service.  The clients send messages to, and receive random messages from, the third-party service.  The client's server opens a channel to our web server via a secure socket in order to receive the incoming messages (and not have to poll the server every few minutes).</p>
  
  <p>My question is: is it safe to leave this channel open indefinitely, or should we periodically close and re-open it to obtain new credentials (session keys)?  If the latter, how often (hourly, daily, weekly) would be considered "best practice"?  I've found a lot of information on secure communications, but nothing to answer this specific question.</p>
  
  <p>Thanks</p>