HP-UX TN3270 R7 Administration Guide

Understanding TN3270
What Is TN3270?
Chapter 116
The TN3270E features are supported only if the directly connected host,
or the communications product that provides the TN Server function,
also supports the TN3270E features. When the connection is established,
the host or communications product negotiates with the TN3270 product
to determine the level of support.
You can configure the level of support that you desire for the TN3270
product by specifying a value for the tn3270_support field in the host
record. You can determine the level of support that was negotiated by
looking at the Control Display Sessions dialog box or the Control Printer
Sessions dialog box. For more information about these dialog boxes, refer
to the TN3270 Users Guide.
TN3270 does not provide support for the following functions that are
described in the various RFCs that are supported:
• The device type IBM-DYNAMIC. The device type that corresponds to
the configured display model is used instead.
• Keep-alive messages, although it does respond to them. If a TCP/IP
connection is lost, the loss is detected when the user presses a key
that causes data to be sent to the host.
• The SYSREQ key on non-TN3270E connections.
• Renegotiation of device type, LU, or TN3270E functions on a
connection that is already open.