IBM 3745
| Industry | Computer hardware |
|---|---|
| Predecessor | 37xx series communications controllers |
| Founded | 2002 |
| Defunct | 2002 |
| Headquarters | Havant, Hampshire , United Kingdom |
| Products | Communications controllers for IBM mainframe platform |
| Owner | IBM |
The IBM 3745 represents the last iteration within the 37xx series of communications controllers designed for the IBM mainframe platform. By the middle of 2009, the number of active larger 3745 units had decreased to over 7,000, compared to more than 20,000 units in operation back in 2007. The 3745 and its counterpart 3746 models found extensive application across sectors such as finance, insurance, retail, and various governmental organizations globally. Nonetheless, the majority of enterprises have since phased out the use of the 3745. Modern replacements include IBM's Enterprise Extender and the Communication Controller for Linux on System z (CCL), which have largely superseded these legacy devices. Although IBM discontinued production of new 3745 hardware in September 2002, it continues to offer worldwide maintenance services, microcode enhancements, and software support for components including NCP and virtual telecommunications access method (VTAM). Official end-of-service announcements have been made for regions such as Japan, Europe, and the Middle East; however, no such declarations have been issued yet for the Americas or certain parts of Asia.
Among the most prevalent configurations are the single Central Control Unit (CCU) 3745-31A and the dual CCU 3745-61A models, commonly utilized alongside the 3746-900 expansion chassis (900 frame). This expansion frame accommodates various front-end connections including multiple T1, token ring, V.35, and V.24 interfaces, while interfacing with the mainframe through several ESCON serial fiber optic channels. An IBM Service Processor operating on IBM OS/2 equipped with proprietary software manages both operator and service-level interactions for these systems.
Production
Manufacturing of the 3745/3746 product range was carried out by Xyratex Technology Limited at their facility located in Havant, Hampshire until production ceased in 2002. Remaining stocks comprising new units, features, spare parts, and components were subsequently acquired by Mid-Atlantic Research and Services, Inc., which operated a remanufacturing plant in Maryland to provide upgrade kits and replacement parts to organizations still dependent on these controllers for essential network operations. This remanufacturing activity continued until late 2013. In 2014, Enterprise Infrastructure Solutions, LLC (EIS), based in Mokena, Illinois, purchased Mid-Atlantic Research for an undisclosed amount.
Replacements
Rather than offering a direct hardware successor compatible with all interfaces of the IBM 3745/3746 models, IBM supplies a software emulation solution named Communications Controller for Linux on System z (CCL), which replicates a portion of the original functionalities. CCL operates on mainframes running Linux on System z and maintains use of the licensed Network Control Program (NCP) from the earlier hardware. Physical connections are facilitated through IBM OSA adapters, with support for low to medium speed lines provided via router ports. Additionally, many organizations transition away from protocols native to the 3745 and CCL platforms by adopting SNA and TCP/IP protocol capabilities through z/OS Communications Server.