TN3270
TN3270 service utilizes the features of Host Integration Server to obtain mainframe access and to address issues such as security and redundancy. TN3270 service supports the TN3270, TN3287, and TN3270E protocols, providing terminal emulation and printing capabilities.
To provide for TN3270 service, in Host Integration Server you create connections and LU definitions that map to the mainframe. TN3270 communicates with Host Integration Server using the logical unit application (LUA) API. Therefore, all LUs configured for use with the TN3270 service must be LUA LUs. The LUA LUs and LUA pools defined for the Host Integration Server computers can then be assigned to the TN3270 service using the drag-and-drop method. When the system is activated, the LUA LUs become available for TN3270 clients to access mainframe applications.
Redundancy involves SNA local nodes and link services. Each Microsoft Windows domain can contain one or more SNA subdomains. LUA LUs from multiple servers can be assigned to the TN3270 service. This results in client sessions distributed among the participating servers in the subdomain, balancing the load. This also allows redundancy between Host Integration Server computers. If one server goes down, a client computer can then access LUA LUs on a different server.
Similarly, a server can be configured with redundant host links to increase fault tolerance and bandwidth.