IBM 3720
The IBM 3720 was a communications controller made by IBM, suitable for use in an IBM System/390. Official service support was withdrawn in 1999 in favour of the IBM 3745. The IBM 3720 is unrelated to the similarly-numbered IBM 3270 display terminal.
References
This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.