This standard specifies the Single-mode fiber Physical Layer Medium Dependent (SMF-PMD) requirements for the Fiber Distributed Data Interface (FDDI). FDDI provides a high bandwidth (100 megabits per second) general purpose interconnection among computers and peripheral equipment using a fiber optic waveguide as the transmission medium. The FDDI may be configured to support a sustained transfer rate of approximately 80 megabits (10 megabytes) per second. The FDDI may not need the response time requirements of all unbuffered high speed devices. The FDDI establishes the connection among many stations distributed over distances of several kilometers in extent. Default values for FDDI were calculated on the basis of 1000 physical connections and a total fiber path length of 200 kilometers (see MAC Standard - ANSI X3.139-1987).