LTE: What is the difference between Release with redirect & Session continuity ?

Question

I gone through the RFC4006 but didnt get the context of below paragraph

   Certain applications require multiple credit-control sub-sessions.
   These applications would send messages with a constant Session-Id
   AVP, but with a different CC-Sub-Session-Id AVP.  If several credit
   sub-sessions will be used, all sub-sessions MUST be closed separately
   before the main session is closed so that units per sub-session may
   be reported.  The absence of this AVP implies that no sub-sessions
   are in use.

But here my question is
1. What could be the types of Multiple credit-ontrol Sub-session?
2. How can we include different cc-sub-session-ID for each sub-session, please give me an example with message structure using CCR message.

Answer 1

Session continuity term is used when UE moves from LTE to other radio access technology (3G/2.5G) through handover signalling. By handover signalling, target radio node is prepared and current eNodeB informs UE to which node it should go and data path changes LTE to 3G.

While in case of re-direction, target node is not prepared, network simply ask UE to move other node by using re-direction message.