Data Communications Networking Devices - 4th Ed.pdf

592 ________________________________________________ LAN INTERNETWORKING DEVICESFigure 5.32 Using PCOM/3270 to select an appropriate attachment method when using acoaxial cable adapter for host communicationsplaced over the IEEE 802.2 attachment method. Thus, if we were con®guring aLAN station or an Ethernet or Token-Ring network connected to a S/390 via aTIC or a similar gateway method, we would select that attachment method.Once you select your attachment method, you can customize your workstation'ssession parameters. Figure 5.34 illustrates the customization screen for an SDLCconnection from a PC to a S/390 host. Although the default screen display of 24lines by 80 columns is shown, PCOM/3270 supports a number of screen sizeoptions that work relatively well with SVGA-based workstations. For example, ifyour requirements include a 132-column display you can easily adjust the screensize by a simple point and click operation.TN3270 operationsOne of the more interesting methods for accessing IBM mainframes is via a specialversion of Telnet known as TN3270. Through the use of a TN3270 program youcan access IBM mainframes connected to the Internet via the Internet, as well asvia workstations on a LAN operating a TCP/IP protocol stack. This capabilityresults from the fact that TN3270 represents a TCP/IP program that operates ontop of a TCP/IP protocol stack.