M13 deployment, the technology that enables multiple T1 delivery from a single T3, is a fairly elementary yet important art for telecommunications carriers. Demand for T1s is affected by existing Remote Terminals (RTs) that are space constrained. Supplying a carrier-class multiplexer that can significantly increase T1 output while minimizing space has been the challenge for telecommunications equipment providers. Carriers facing costs for IP addressing save money because M13 capability can be added yet each MX2820 uses only a single IP address. In areas where multiple M13s are needed, the ADTRAN MX2820 High-Density M13 Multiplexer frees up valuable rack space with a high-density chassis. The MX2820 houses up to 18 multiplexer cards to provide 9 redundant M13 multiplexers in a 23-inch chassis and 2 rack units of space. Up to 7 redundant M13 multiplexers can be based in a 19-inch chassis. In addition, the MX2820 can provide up to 72 M13s in a 7-foot bay.