Cal Adventist Federal Credit Union

Automation Access recently completely rewired the Cal Adventist FCU building with Cat-5 cable and appropriate hardware in preparation for a move from serial termials to network workstations. Over 3000 feet of cable was pulled, two cables per workstation for any combination of network, serial connection or telephone. We pulled abandoned cable for several generations of computer systems out of the ceiling.

For many years Cal Adventist has used Data General serial terminals wired to a multiplexor which combined all their traffic for connection over a single phone line. At the Fiserv data center in Wisconsin, a similar multiplexor separated the traffic and connected it to the serial ports of a Data General computer. Printers were connect the same way, and there were no local computers on the credit union system.

Today, PC workstations are slowly displacing the terminals. Both PCs and terminals are connected by serial cabling to a "port server" which converts their activity to network packets. In Wisconsin, the Unix host interprets the traffic directly with software, so no port servers are required there. The PCs use "terminal emulation" software so the host thinks they are terminals. Eventually, each PC will get a network card and will talk directly to the host over the network. The port server will serve only printers.

We replace a hulking multiplexor cabinet and a heaping tangle of wire on the floor behind it with this (relatively) neat wall mounted backboard. The devices, on the backboard are (from the bottom):

Digi Port Server, converting 16 serial connections to network traffic.
Digi 16-port Expansion (not needed, but Fiserv sent it).
DSU/CSU connects the router to a T1 telephone line.
Box of spare connectors.
Cisco Access Router including another 16-port port server.
Cisco 10/100 Ethernet Hub.
110 Frame for telephone connections (on wall).
Patch Pannel (48-port Cat-5) to which all workstation wiring is terminated.

That lonely wire across the bottom of the backboard is the T1 connection over which all traffic connects to Fiserv. Currently, there is no local network traffic at all.

When PCs have replaced the terminals and are in turn converted to network rather than serial, the Digi boxes will go away. The Cisco router has enough serial ports for the printers. Obviously, the hub will have to be replaced with one offering more ports since all workstation connections will go to the hub.

The system will always emulate serial connections over the network and will never become a "true network" system, because a T1 line has no hope of supporting the traffic of a Windows network. Even using Windows Terminal Services the system would be slower and cost hundreds of times more. A Web based thin client model would work, but still at many times the cost of a Unix terminal system.

Another system feeding through the same backboard is this CTI (Computer Telephone Integration) system. This system allows clients of the credit union to get loan quotes and other information from their telephone at any time of day or night. This unit contains the "front end" that converses with the caller, and in turn communicates directly with the Fiserv computers in Wisconsin. It too replaced a huge noisy box with a heap of telephone wires and serial cables.