Echo Mux from Black Box
Try this modular Echo Mux from Black Box that uses the latest chip set technology to provide a versatile, user-friendly 2-Mbps multiplexor.
The basic Echo Mux provides two X.21 channels, and an expansion card increases the number to four, giving you the benefits of sharing expensive E1 bandwidth.
MUX - Multiplexer
MicroMux SP-3i: The ultimate in 2-Mbps G.703 connectivity.
The MicroMux SP-3i gives you the features of the SP-1 and SP-3 with the added benefit of local and remote management.
modular echo mux
wave division multiplexer
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