-In Magnesium SR0, the interconnection of the PCE with GNPY (Gaussian Noise Python), an
-open-source library developed in the scope of the Telecom Infra Project for building route
-planning and optimizing performance in optical mesh networks, is fully supported. Impairment
-aware path computation for service of higher rates (Beyond 100G) is planned across Phoshorus
-releases. It implies to make B100G OpenROADM specifications available in GNPy libraries.
-
-If the OSNR calculated by the PCE is too close to the limit defined in OpenROADM
-specifications, the PCE forwards through a REST interface to GNPY external tool the topology
-and the pre-computed path translated in routing constraints. GNPy calculates a set of Quality of
-Transmission metrics for this path using its own library which includes models for OpenROADM.
-The result is sent back to the PCE. If the path is validated, the PCE sends back a response to
-the service handler. In case of invalidation of the path by GNPY, the PCE sends a new request to
-GNPY, including only the constraints expressed in the path-computation-request initiated by the
-Service Handler. GNPy then tries to calculate a path based on these relaxed constraints. The
-result of the path computation is provided to the PCE which translates the path according to the
-topology handled in transportPCE and forwards the results to the Service Handler.
-
-GNPy relies on SNR and takes into account the linear and non-linear impairments
-to check feasibility. In the related tests, GNPy module runs externally in a
-docker and the communication with T-PCE is ensured via HTTPs.
+In Neon SR0, the PCE calculates the OSNR, on the base of incremental noise specifications provided
+in Open ROADM MSA. The support of unidirectional ports is also added. The interconnection of the PCE
+with GNPY (Gaussian Noise Python), an open-source library developed in the scope of the Telecom Infra
+Project for building route planning and optimizing performance in optical mesh networks, is supported
+since Magnesium SR0. This allowed introducing impairment aware path computation for (Beyond 100G)
+services across Phoshorus releases.
+
+In Argon, we introduce autonomous impairment aware path computation, leveraging OpenROADM yang
+specification catalog (R10.1), which translates the optical specifications provided in the MSA into
+models understandable by the controller. To each disaggregated element crossed along the path
+(Transponders, ROADM add/drop modules and degrees), is associated an operational mode, for which each
+physical parameters is described in the catalog. This allows evaluating the degradations that each
+element, whether it is a device of fiber span, brings to the signal transmission. The resulting
+Optical Signal to Noise Ratio is calculated, as well as the penalties associated with the cumulated
+chromatic dispersion, Polarisation Mode Dispersion (PMD), Polarization Dependant Loss (PDL)… and the
+non-linear contribution is evaluated.
+
+All of this is done in accordance with OpenROADM optical specifications. Handling OpenROADM specification
+catalogs improves the upgradability of the code, since the future evolution of the specifications only
+implies to add new operational modes to the catalog while the associated code remains unchanged.
+
+In Argon SR0, to benefit from this new functionality, the specification catalog must be manually loaded
+into the data store. The catalog includes 2 different parts, the first being dedicated to the
+translation of OpenROADM specifications, the second (optional) being dedicated to specific operational
+modes for transponders used in “bookended” mode (same transponders on both ends of the path). The
+automatic filling of the first part of the catalog is planned in Ar SR1. In this release will also be
+supported the 2 RPCs used to fill the different parts of the catalog :
+- **add-openroadm-operational-mode-to-catalog**
+- **add-specific-operational-mode-to-catalog**
+
+Autonomous impairment aware path computation is triggered in Argon for any path at the WDM layer,
+whatever is the service rate. The transmission margin is evaluated in both direction and the result is
+provided in INFO Logs. GNPy is used in a second step to enforce path validation. Indeed, it gives
+complementary information to the calculation made from OpenROADM specifications, with a finer assessment
+of non-linear contribution, and potentially a consideration of the interaction with other channels
+already provisioned on the network. This last capability will be added across Argon releases.
+The PCE forwards through a REST interface to GNPY external tool the topology and the pre-computed path
+translated in routing constraints. GNPy calculates a set of Quality of Transmission metrics for this path
+using its own library which includes models for OpenROADM. The result is sent back to the PCE. If the
+path is validated, the PCE sends back a response to the service handler. In case of invalidation of the
+path by GNPY, the PCE sends a new request to GNPY, including only the constraints expressed in the
+path-computation-request initiated by the Service Handler. GNPy then tries to calculate a path based on
+these relaxed constraints. The result of the path computation is provided to the PCE which translates
+the path according to the topology handled in transportPCE and forwards the results to the Service
+Handler.
+
+GNPy relies on SNR and takes into account the linear and non-linear impairments to check feasibility.
+In the related tests, GNPy module runs externally in a docker and the communication with T-PCE is
+ensured via HTTPs.