An SSL session is established between two nodes (via ip addresses,layer 3) or between applications ( layer 4) ? Thanks

  • Neither layer 4 or 3. Its on layer 5 or 6 or 7. Depending on the application.
    – Cyberduck
    Commented Dec 10, 2019 at 20:48
  • Let's suppose i want to connect to a server encrypting both skype and a browser with SSL (for example) do i need 2 sessions ?
    – AleWolf
    Commented Dec 10, 2019 at 20:50

1 Answer 1


IP, and TCP/IP pre-dates the OSI model. Layers 1-4 of OSI almost map to the network and TCP/IP stack (which TLS sits on top of) but if you keep trying to explain one in terms of the other you're going to become lost; there are at least 3 session layers in a HTTP/2 application (TCP, TLS, HTTP), usually 4 (+application state) and sometimes more (+authentication).

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