HP-UX SNAplus2 R7 General Information

SNAplus2 Networking Solutions
Adding APPN Capability
Figure 3–4 SNA Network Including APPN
APPN Network
Downstream LU on EN
uses DLUR
to communicate with host
across APPN network
Server
acts as
PU concentrator
DLUR
support
Downstream LU
on EN uses
PU concentration
to communicate
with host
SNA Server 2
SNA Server 1
Other branch
configurations
Host (includes DLUS)
FEP
Controller
NN
NN
NN
NN
EN
EN
A peer network is connected to the existing multiple client/server system. APPN is especially appropriate for groups
of PCs and workstations on LANs, because such networks undergo high levels of change. The dynamic configura-
tion and route calculation of APPN is of crucial importance to the scalable growth of the network.
The original SNAplus2 servers can connect simultaneously to both APPN and pre-APPN nodes. The server provides
PU concentration functionality to downstream LUs. PU concentration enables host-based SNA applications to be
run on the APPN network, while reducing the number of links required to the host in a fashion that is completely
transparent—both to the host and to the downstream LU. This function enables legacy applications to run on the
APPN network without modification, and reduces the connectivity requirements for communication with the host
from the APPN network.
In addition, the financial services division writes new distributed applications that run on the SNAplus2 network
nodes and end nodes in the APPN part of the network. The APPN network enables new machines to access the
applications automatically as they are connected to the network, without requiring reconfiguration at the host for
every new computer that is added.
These new applications make use of the increased processing power that is available on local workstations, without
increasing the volume of the traffic to the host.
By doing more processing locally, this configuration decreases the demand for host processing so that the remaining
corporate central processing can be done more quickly.
As the APPN part of the network grows, SNAplus2 DLUR functionality (running in conjunction with DLUS on
the host) supports corporate back-level applications (such as 3270) transparently across the APPN network. DLUR
provides a migration path from subarea SNA applications to APPN.
34