The RS-449 standard (aka EIA-449 or TIA-449) was originally designed as the successor to the more common RS-232 standard used on PCs. It supports RS-422 balanced signals and RS-423 unbalanced signals, with data rates up to 10 Mbps over very short distances and 2 Mbps over more reasonable distances.
Although the standard was withdrawn in September 2002, it is still used with some network communications equipment where high throughput and/or long distances are required. The RS-449 cable is also used for V.36 modem equipment.
This RS-449 cable uses DC-37 (aka DB-37) male connectors on each end and is wired straight through, pin for pin. The connectors are molded onto the cable and feature thumbscrews for securing the plug to the socket.