Successful RS-232 data transmission depends on many variables that are specific to each environment. The general rules above are empirical and have a lot of safety margins built-in. Most analog modems and most of the older computers and serial equipment use this connector. Most of the networking equipment and newest servers use RJ-45 connectors for serial communication. Every equipment vendor has its pin assignments.
Most connectors have two versions.
They cross transmit and receive data signals between the two sides and there are many variations on how the other control signals are wired. After that, purchase the standard pre-made cables from a computer store or cable vendor. For custom cables, refer to the cable diagrams to build your own cables or order them from Cyclades or a cable vendor. This cable is standard, but it may be difficult to find it pre-made. This custom cable can be ordered from Cyclades or other cable vendors.