25pair
25-pair, or 25-pair cable, is a type of telecommunications cable that contains 25 twisted copper pairs inside a single outer sheath, totaling 50 conductors. It was widely used for analog voice circuits and early data links, particularly in office buildings, central offices, and distribution frames, where many lines needed to be routed over a single run. The format supported multi-line connections and cross-connecting between equipment.
Construction and identification: Each pair is two insulated copper conductors. Pairs are identified by the established
Applications and current status: While most new networks have moved to fiber or higher-density copper solutions
See also: Twisted pair cables, telephone distribution cable, 50-pair cables.