– If this retry fails, wait 60 seconds (the value of

Short retry timer

).
– Retry the primary DLUS. If this retry fails, retry the backup DLUS. This is
attempt #1 of the

Short retry count

.
– If this fails, wait 60 seconds (the value of

Short retry timer

).
– Retry the primary DLUS, and then the backup DLUS. This is attempt #2

Short

retry count

.

Short retry count

is now exhausted.
– If the retry still fails, wait 300 seconds (the value of

Long retry timer

). Then
retry the primary DLUS. If this retry attempt fails, retry the backup DLUS.
– As long as the retry fails, continue to retry the primary and the backup DLUS,
waiting 300 seconds between retry sequences, for as long as the DSPU is
requesting ACTPU.
APPN Implementation on the Router Using DLSw
The router also supports APPN over DLSw for connectivity to nodes through a
remote DLSw partner.An example is shown in Figure 3. This support allows
customers with DLSw configurations to migrate their networks to 2210.
Note: It is recommended to use APPN over direct DLCs when available instead of
APPN over DLSw.
APPN configuration restrictions using DLSw:
vConnectivity through remote DLSw partners only
vOnly 1 DLSw port per router
vUse of a locally administered MAC address
vHPR is not supported on DLSw ports
vDLSw ports cannot be members of connection networks
vParallel TGs are not supported on DLSw ports
See “Configuring the Router as an APPN Network Node”on page 26 to configure
APPN using DLSw.

How APPN Uses DLSw ports to Transport Data

When APPN is configured on the router to use Data Link Switching (DLSw) port,
DLSw is used to provide a connection-oriented interface (802.2 LLC type 2)
between the APPN component in the router andAPPN nodes and LEN end nodes
attached to a remote DLSw partner.
Bridged Frames
DLSw Router
DLSw Router
End
Node
IP
Ring
APPN
DLSw
TCP
WAN
Ring
Figure 3. Data Flow in anAPPN Configuration Using DLSw Port
APPN
Chapter1. APPN 43