Know your gear
The 356A Adapter has a 50-pin, male or female telco connector, which distributes the pairs from a 25-pair connectorized telco cable to eight 8-pin RJ45 modular jacks (only six of the eight pins are connected on each jack).
The adapters are used to join connectorized 25-pair cable to 4-pair cords equipped with RJ45 modular plugs, such as linking clusters of balun adapters onto UTP connecting hardware in a telecommunication closet, equipment room, or computer room. These adapters should not be used with devices that require connections to all eight pins of the RJ45. The 356A can support applications running at 10 Mb/s or less.
The adapters are used to join connectorized 25-pair cable to 4-pair cords equipped with RJ45 modular plugs, such as linking clusters of balun adapters onto UTP connecting hardware in a telecommunication closet, equipment room, or computer room. These adapters should not be used with devices that require connections to all eight pins of the RJ45. The 356A can support applications running at 10 Mb/s or less.