Receiver-detected error examples

For simplicity, in the following series of figures, all examples assume only-in-chain (OIC) messages for flows in both directions. Also the bracket and ERP protocol are considered symmetrical in that either half session can initiate the bracket or ERP procedures as illustrated.

For all session terminations not involving system failures, ATTACH information is recovered and backed up to the last sync point. In the examples that follow, IMS is the receiver.

Figure 1. Example of receiver ERP for an IMS component defined as SINGLE1
Flow 1 and flow 2 have multiple arrows between PHS (IMS) and SHS with various labels on the arrows, such as OIC,BB,CD, EXCP RSP (Receiver ERP), OIC,EB (ERP message), and others.
Figure 2. Example of receiver ERP for an IMS component defined as SINGLE2
Flow 1 and flow 2 have multiple arrows between PHS (IMS) and SHS with various labels on the arrows, such as OIC,BB,CD, EXCP RSP (Receiver ERP), OIC,CD (ERP message), and others.
Figure 3. Example of receiver ERP for an IMS component defined as MULT1
Flow 1 and flow 2 have multiple arrows between PHS (IMS) and SHS with various labels on the arrows, such as OIC,BB,CD, EXCP RSP (Receiver ERP), OIC,(ERP message),CD, and others.
Figure 4. Example of receiver ERP for an IMS component defined as MULT2
Flow 1 and flow 2 have multiple arrows between PHS (IMS) and SHS with various labels on the arrows, such as OIC,BB,CD, EXCP RSP (Receiver ERP), OIC,CD (ERP message), and others.

In this case, the receiver is the other subsystem. The IMS action follows selective receiver ERP sequence.

Figure 5. Example of demand-paged output with receiver-detected error
Flow 1 and flow 2 have multiple arrows between PHS (IMS) and SHS with various labels on the arrows, such as ATTACH DPN=MID,OIC,data,(BB)CD, ATTACH DPN=,DQN=X,OIC,CD, and others.

IMS action: Return message to queue and continue output.

In this example, flow 1 shows the receiver using receiver ERP to reject a demand-paged message. Flow 2 shows alternate methods with the same end result, but not involving an ERP message from the receiver.