According to the Nokia Optical Networking documentation, a Shared Risk Group (SRG) is defined as 'a set of network resources that share a common failure risk. When a resource in an SRG fails, the other resources in the group are also affected.' This can include fibers, boards, nodes, and other network resources. The SRG concept is used in network design and protection mechanisms to ensure survivability and minimal impact on service in case of a failure.

Different wavelengths propagate at different speeds within the same media and therefore different colors travel in the fiber with different speed. This phenomenon is known as chromatic dispersion and causes light to spread out as it travels through the fiber over distance, leading to signal attenuation and distortion. The fiber attenuation does not introduce inter-channel interference, but it can cause attenuation of the signal. Different channels have different bandwidths, but this does not affect CD performance.

It is possible to open and manage EPT designs that are created with different releases than the release installed on the local workstation, however only designs created with current and older releases can be opened and edited. Designs created with an older release can be opened by a current release but changes cannot be made.

The OSNR is defined as the ratio between the average optical signal power and the average optical noise power over a specific spectral bandwidth. This is also known as the signal-to-noise ratio (SNR), and it is a measure of how much signal is present in the optical signal compared to the noise, usually expressed in decibels (dB).

Node synchronization is a process of keeping the NFM-T database in sync with the nodes in the network. The synchronization process will download all the items from the node, including NE parameters, ports, alarms, internal links, etc., to the NFM-T database. This ensures that the NFM-T database is up to date and the network is running efficiently.