Siemens TSU NT 22 O¶
This is a Optical Line Termination (OLT) for two E1 circuits within the Siemens Fastlink system.It speaks to the ONU via a bi-directional single-mode optical fibre with a supposedly proprietary protocol/framing. There are two wavelengths in use:
- 1550 nm in the downlink to the NT
- 1300 nm in the uplink direction to the LT
As one can see, it actually houses a module in the Siemens_FastLink form-factor with its two DIN backplane connectors. This likely means the module is (mostly?) identical to the LT side used in the transport network, the LTO/LT module.