Visara CNA-8000 Installation - Manual (Page 49)

CNA-8000 Installation and Configuration
707158-003 3-7
TN3270E Gateway
The TN3270E Gateway function of the CNA-8000 is an optional feature.
TN3270E Client sessions are implemented as SNA 3270 sessions by the CNA-8000.
Each session is handled by the host as a dependent SNA LU session. In the SNA
environment LU sessions require a PU function to manage them. On the CNA-8000 this
is provided by a PU type 2.0 Host Circuit. Each Host Circuit provides support for up to
253 concurrent dependent LU sessions. Multiple Host Circuits may be configured on the
CNA-8000 to support the number of TN3270E clients that are to make use of it.
To make use of switched PU/LU definitions in VTAM through the XCA gateway feature
of the CNA-8000, each Host Circuit is made to appear as if it were a remote downstream
SNA node. To accomplish this each Host Circuit is assigned to one of the configured
network adapters and is assigned a virtual MAC address and virtual SAP.
TN3270E clients connect to the CNA-8000 by targeting the IP address of one of the
CNA-8000’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 CNA-8000, the client will be allowed to connect
under the conditions allowed by the CNA-8000.
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 CNA-8000
options. Combinations of the different options described below can be deployed and
supported by the CNA-8000.
Static Definitions or Pooled Definitions:
Each time a client connects, they can be given a specific LU assignment from a specific
Host Circuit, or they can be given a session from a session pool. Session pools allow the
same LU resource be shared by multiple users on a first-come-first-serve basis. Session
pools consist of any number of LUs from one or more Host Circuits that have been
grouped together and assigned a name. Each LU can be assigned to one or more pools
and can be statically mapped as well. Usually however, you will want to have them
assigned to either a pool or a static assignment.
Encryption Used or Not:
Whether Encryption is used or not is configurable on a Listening Port by Listening Port
basis. This option must be matched by the client exactly or no connection will be
accepted.