The TCX1000-2D8CMD is a standalone C-Band two-degree eight channel colorless passive multiplexer/demultiplexer. It is a rack-mounted module that is installed alongside the TCX1000-RDM20. Each module combines the signals at eight channel input ports (C0 to C7IN ports) and broadcasts the multiplexed signals out of two Line-side direction ports (L0 OUT and L1 OUT) ports. The module also combines the signals at the two Line-side input ports (L0 IN and L1 IN ports) and broadcasts the demultiplexed signals out of eight channel output ports (C0 to C7OUT ports).

One of the two common Line ports of the multiplexer/demultiplexer is connected to one of the TCX1000-RDM20 ports and provides eight ports for transceiver connections. This allows for more transceivers to be connected to the TCX1000-RDM20, while still maintaining the spectrally programmable (colorless) operation.

The TCX1000-2D8CMD also provides a second Line port which can be connected to another TCX1000-RDM20 degree and allow channels to be transmitted and received from two directions. This is based upon passive splitting and combining, so identical multiplexes come out of the two Line ports and the TCX1000-RDM20 needs to select which (or both for 1+1 protection) are sent through to the TCX1000-RDM20 Line ports. Also, the drop side of the TCX1000-RDM20 determines which path gets received. Both paths (from both ROADM directions) cannot be operational at the same time.

The TCX1000-RCK-1 kit chassis is a 1RU mechanical assembly that can accommodate up to three TCX1000-2D8CMD modules. It allows the modules to be rack mounted in standard 19-inch, 21-inch, and 23-inch racks.

The TCX1000-2D8CMD measures 5.10 in. (12.95 cm) high, 6.25 in. (15.87 cm) deep, and 1.12 in. (2.84 cm) wide. The module weighs 0.57 lb (0.25 kg).