Here's one of many good diagrams you can find on the handshake
http://publib.boulder.ibm.com/infocenter/cicstg/v7r0m0/topic/com.ibm.cics.tg.doc/ctgwin/hndshake.gif
(courtesy - http://publib.boulder.ibm.com/infocenter/cicstg/v7r0m0/index.jsp?topic=/com.ibm.cics.tg.doc/ctgwin/sslauth.htm )
http://publib.boulder.ibm.com/infocenter/cicstg/v7r0m0/topic/com.ibm.cics.tg.doc/ctgwin/hndshake.gif
(courtesy - http://publib.boulder.ibm.com/infocenter/cicstg/v7r0m0/index.jsp?topic=/com.ibm.cics.tg.doc/ctgwin/sslauth.htm )