+-----------+------------------------+-----------+-----------+ | Handshake | Negotiation |Continuity |Termination| | Phase | Phase | Phase | Phase | | | | | | | X ---------> Y --> X --> Z --> X ---> Y --> X ---> X | | | A | A | | A | | | | | | | | | | | | | | | | +-----+ +-----+ | +-----+ | | | | | | | +------------------------------------------------+-----------+