The Nokia power commissioning system, as implemented in platforms like the 1830 PSS, is an automated procedure designed to discover network topology and set optical power levels. This system is engineered to support the most common optical network configurations, which include both linear (chain) and ring topologies. The commissioning process operates over the Optical Supervisory Channel (OSC), which establishes communication between adjacent nodes. A "through connection" refers to a data wavelength that passes through a node's equipment (e.g., a ROADM) without being terminated. This does not affect the OSC link, which is terminated at each node. Therefore, the commissioning process is not halted and continues to discover the next node in the sequence.

A. The commissioning process is not stopped by a through connection, as it relies on the node-to-node OSC link, which is independent of data wavelength paths.

B. The system is not limited to ring topologies; linear (chain) configurations are also fully supported by the automated power commissioning procedure.

C. While it is correct that a through connection does not stop the system, the statement that the system must be a ring only is inaccurate.

1. Nokia 1830 PSS Engineering and Planning Guide, Release 11.2 (Document ID: 3KC-13003-AAAA-TCZZA), Section 3, "Network configurations and topologies". This section details the support for various network structures, explicitly including linear chain and ring topologies for WDM systems.

2. Nokia 1830 PSS Commissioning Guide, Release 11.2 (Document ID: 3KC-13005-AAAA-TCZZA), Chapter 4, "System commissioning procedures". This chapter describes the automated power commissioning process, explaining that it uses the OSC to sequentially discover and configure adjacent nodes. The procedure is designed to progress along the entire line system (linear or ring) and is not impeded by the presence of through-connected service wavelengths at intermediate nodes.