APPN flows

This appendix describes the flows between APPN end nodes, network nodes, interchange nodes, and the subarea network. The flow diagrams are divided into the following categories:

Table 1 lists all the APPN flows illustrated here.

Table 1. Index of APPN flows
APPN flow Page
CP-CP session flow Page
Activating a CP-CP contention loser session Figure 1
Activating a CP-CP contention winner session Figure 1
Activating an APPN Host-to-Host Channel Figure 1
Activating a leased APPN Node type 2.1 Figure 1
Host CP initiating deactivation of CP-CP session Figure 1
Remote node initiating deactivation of CP-CP session Figure 1
   
Dependent LU server flow Page
Single subnetwork  
Activating resources  
CPSVRMGR pipe activation, DLUR-Initiated Figure 1
CPSVRMGR pipe activation, DLUS-initiated Figure 1
Dependent LUs, dynamic registration and activation of Figure 1
Dependent LUs, activation of pre-defined Figure 1
  Figure 1
SSCP-PU session activation race Figure 1
Deactivating resources  
CPSVRMGR pipe deactivation Figure 1
Downstream PU outage Figure 1
REQDISCONT (immediate) received from downstream PU Figure 1
REQDISCONT (normal) received from downstream PU Figure 1
LU-LU sessions  
APPN PLU-initiated to a dependent SLU Figure 1
Session termination, USS flows for Figure 1
USS SLU-initiated to APPN PLU Figure 1
USS SLU-initiated to subarea PLU Figure 1
SSCP-PU, SSCP-LU session deactivation  
Forced Figure 1
Normal Figure 1
With Giveback (ANS=CONT) Figure 1
With Giveback (ANS=STOP) Figure 1
Cross subnetwork  
PLU-Initiated Session with DLUS and DLUR within Different Subnetworks Figure 1
PLU-Initiated Session with DLUS and PLU in one Subnetwork and DLUR in Another Figure 1
SLU-Initiated Session with DLUS and DLUR within Different Subnetworks Figure 1
Directory services flow Page
Locate resource  
APPN and subarea Network Figure 1
APPN network, complex Figure 1
Complex APPN network using more than one CDS Figure 1
CP-CP session terminates Figure 1
CP network broadcast initiation Figure 1
EN to NN Figure 1
EN to NN to EN Figure 1
EN to NN to NN to NN Figure 1
EN to NN to subarea network Figure 1
EN to NN to two ENs Figure 1
NN receives network broadcast request Figure 1
NNS of the OLU is at pre-V4R2 level Figure 1
Directory search verification reduction Figure 1
SLU-initiated session Figure 1
Register resource  
EN to NN to CDS Figure 1
With error recovery Figure 1
High Performance Routing (HPR) flow Page
Rapid-transport protocol (RTP) connection over portion of session path Figure 1
Rapid-transport protocol (RTP) across composite nodes with a T2.1 connection through NCP Figure 1
Rapid-transport protocol (RTP) across composite nodes with a T2.1 connection through VTAM® Figure 1
Rapid-transport protocol (RTP) across composite nodes with a virtual-route-based transmission group, NCP does ANR routing Figure 1
Rapid-transport protocol (RTP) across composite nodes with a virtual-route-based transmission group, VTAM does ANR routing Figure 1
Two rapid-transport protocol (RTP) nodes with a T2.1 connection Figure 1
Two rapid-transport protocol (RTP) nodes with a virtual-route-based transmission group Figure 1
LU-LU sessions flow Page
APPN network...NNS--EN (PLU)  
SLU-initiated, no queueing Figure 1
SLU-initiated, queued by the PLU Figure 1
APPN network...NNS--EN(SLU)  
PLU-initiated, no queueing Figure 1
PLU-initiated, queued by the SLU Figure 1
APPN network (PLU)…ICN==SA(SLU), PLU-Initiated  
Directed search without required precomputed RSCV Figure 1
No queueing Figure 1
Queued by SLU Figure 1
Search-only flow transformed into a DSRLST Figure 1
USERVAR resolution required Figure 1
APPN network (PLU)…ICN==VR-based TG==ICN…APPN network (SLU)  
PLU-initiated Figure 1
APPN network (SLU)…ICN==SA(PLU)  
Autologon, PLU not available initially Figure 1
SLU-initiated, no queueing Figure 1
SLU-initiated, queued by the PLU Figure 1
CLSDST PASS; SLU is single-session capable  
From APPN to subarea Figure 1
Through APPN Figure 1
EN-NN-EN, PLU-initiated, no queueing (including BIND flows for intermediate network node) Figure 1
EN (PLU)--NNS…APPN network  
PLU-initiated, no queueing Figure 1
PLU-initiated, queued by the PLU Figure 1
PLU-initiated, queued by the SLU Figure 1
EN (SLU)--NNS…APPN network  
SLU-initiated, no queueing Figure 1
SLU-initiated, queued by the PLU Figure 1
Intermediate Network Node (INN) BIND. The LOCATE did not go through this node. Figure 1
SA (PLU)==ICN…APPN network (SLU)  
DSRLIST transforming into PLU-initiated, search-only Figure 1
PLU-initiated, no queueing Figure 1
PLU-initiated, queued by the SLU Figure 1
PLU-initiated, USERVAR resolution required Figure 1
SA (SLU)==ICN....APPN network (PLU)  
Autologon, PLU not available initially Figure 1
SLU-initiated, no queueing Figure 1
SLU-initiated, queued by the PLU Figure 1
Session release request  
SA(PLU)==ICN…APPN network(SLU) Figure 1
SA(SLU)==ICN…APPN network(PLU) Figure 1
Session termination, forced  
SA(PLU)==ICN…APPN Network(SLU), pending active session. PLU is accessible without going into APPN. Figure 1
SA(PLU)==ICN…APPN Network(SLU), queued session Figure 1
SA(PLU)==ICN…APPN Network(SLU), queued session. PLU is accessible without going into APPN. Figure 1
SA(SLU)==ICN…APPN Network(PLU), pending active session Figure 1
Session termination, orderly  
SA(PLU)==ICN…APPN Network(SLU), active session Figure 1
APPN Network(PLU)…ICN==SA(SLU), active session Figure 1
Many abbreviations are shown at the top of the flow diagrams. The following list gives the meaning of those abbreviations:
ANR
Automatic network routing
APPC
Advanced program-to-program communication program
BF
Boundary function
CDS
Central Directory Server
CP
Control point
DLUR
Dependent logical unit requestor
DLUS
Dependent logical unit server
EN
End node
ICN
Interchange node
LU
Logical unit
NN
Network node
NNS
Network node server
PLU
Primary logical unit
PU
Physical unit
PUNS
Physical unit services
RTP
Rapid-transport protocol
SLU
Secondary logical unit
SSCP
System services control point
TP
Transaction program
TSC
Transmission subsystem component