Complex sentence: This is an often cited benchmark in marketing and systems-engineering comparisons, called the "five nines" reliability standard, and is equivalent to having a dial-tone available for all but less than five minutes each year.
Split into simpler sentences: This is an often cited benchmark in marketing and systems-engineering comparisons, called the "five nines" reliability standard. It is equivalent to having a dial-tone available for all but less than five minutes each year.