Visara CCA-3074 Installation - Manual (Page 35)

CCA-3074 Installation and Configuration
707161-003 3-1
Chapter 3. Connectivity Overview
This chapter attempts to give you an overview of how the CCA-3074 works, to give you
more insight as to what is required to properly configure the platform to achieve your
goals. You may wish to review the CCA-3074 Planning manual for additional
information including planning worksheets.
Non-SNA TN3270 Interface
All sessions on the CCA-3074 run as Non-SNA 3270 sessions. The physical host
interface for the CCA -3074 includes both ESCON and FICON, where an emulation of
the old IBM 3174 or 3274 style controller is performed. The primary use of the CCA-
3074 is to provide console access to each host mainframe LPAR. Logically this is
accomplished by defining a CNTLUNIT macro and associated IODEVICE macros in the
host gen to define the 3270 console devices. Each LPAR requires one or more
CNTLUNIT definitions to external consoles through the CCA-3074. Each CNTLUNIT
defined on the host has a corresponding CU (control unit) definition on the CCA-3074.
Each IODEVICE address corresponds to a subchannel over the physical ESCON/FICON
interface and corresponds to sessions defined on the CCA-3074 given to TN3270 clients.
TN2370 clients provide the necessary remote 3270 interface to implement the console
function.
Each CU may be defined to support 1-32 sessions. Not all sessions need to be used as
consoles. It is also common to use some of the sessions for access to VTAM applications
such as TSO or CICS. Each CU defined on the CCA-3074 has a corresponding Host
Circuit associated with it (one to one relationship).
TN3270E clients connect to the CCA-3074 by targeting the IP address of one of the
CCA-3074’s Ethernet adapters and using one of the configured Listening Ports to connect
to. If encryption is expected on the Listening Port, then only clients using encryption will
be allowed to connect. Various TN3270E options get negotiated, and depending on the
configuration of the CCA-3074, the client will be allowed to connect under the conditions
allowed by the CCA-3074.
There are several approaches to managing the remote TN3270 clients. Chances are you
already have clients deployed and a management scheme in place. The purpose of this
section is to describe the many ways management can be accomplished by the CCA-3074
options. Combinations of the different options described below can be deployed and
supported by the CCA-3074.