Visara LINCS Configuration - Manual (Page 175)

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11. TN3270 Client Definitions
The TN3270 Client Definition panel is used to map LINCS 3270 host resources to TN3270
clients. Through configuration of this panel, it is possible to assign specific LUs to a client, or
give LUs from a pool (3270 Host Class). It is also possible to determine whether a password
is required by a client to gain access.
Not all TN3270 emulators are capable of handling the command chaining used by console
devices. Most should work however as VTAM devices.
Specific LUs can be assigned using four different methods:
1. You can have a separate entry on this panel for each client, using the client’s IP
address to determine which resource is assigned to them. (This of course will not
work in DHCP environments.)
2. You can use a different TCP port for each client, so that depending on which port
is used to connect to the 2XL, only a specific LU is given out.
3. The client can request the 2XL resource at connection time using the format “00,06”
to request session “06” on host circuit “00” (or “a,02” to request session “02” on
host “a” on older code versions) from the 2XL. This method can be prohibited by
enabling one of the RPQ options.
4. A nickname file can be set up to associate a requested resource name to a specific
2XL resource.
TN3287 clients typically request their own LU at connection time as an extension of the
Device Type field. As an example, the client would request the following device type IBM-
3287-1@01,16 where the device type is IBM-3287-1 and the extension @01,16 indicates
that host circuit 01, LU 16 (hex) is desired. When requesting specific LUs in this fashion, no
specific entry in the TN3270 Client Definition Panel is required. The LU requested, however
should be defined as part of a 3270 Host Class, set aside for specific LUs that will be requested
by TN3270 clients.
If a client requests a specific LU at connection time, the request takes precedence over what
is configured, unless one of the RPQ options is enabled to limit connections to those configured,
or to ignore all LU requests.
Requests that include invalid information such as a host or class that does not exist will result
in a failed connection attempt.
When attempting to match a resource to a client connection request, the 2XL will search the
configured options based on the order in which they are defined on this panel. Therefore, if
the first entry for a user connecting on port 23 happens to be to get a session from a pool, then
it does not matter that a specific LU assignment was defined further down the panel, they
would get the pooled session instead. For this reason, it is good practice to define specific LU
assignments earlier in the table than pooled resource assignments.
Likewise, when using a nickname file to assign resources the nickname file is searched from
the beginning until the first match is found.
The TN3270 Client Definition Panel is displayed if TN3270 Client Connections are configured