diff --git a/docs/index.rst b/docs/index.rst
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--- a/docs/index.rst
+++ b/docs/index.rst
@@ -13,6 +13,7 @@ in real-world mesh optical networks. It is based on the Gaussian Noise Model.
    install
    json
    excel
+   yang
    extending
    about-project
    model
diff --git a/docs/yang.md b/docs/yang.md
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+(yang)=
+# YANG-formatted data
+
+(yang-equipment)=
+## Equipment Library
+
+The [equipment library](concepts-equipment) is defined via the `tip-photonic-equipment` YANG model.
+The database describes all [amplifier models](yang-equipment-amplifier), all [types of fiber](yang-equipment-fiber), all possible [ROADM models](yang-equipment-roadm), etc.
+
+(yang-equipment-amplifier)=
+### Amplifiers
+
+Amplifiers introduce noise to the signal during amplification, and care must be taken to describe their performance correctly.
+There are some common input parameters:
+
+`type`
+
+: A free-form name which must be unique within the whole equipment library.
+It will be used in the network topology to specify which amplifier model is deployed at the given place in the network.
+
+`frequency-min` and `frequency-max`
+
+: Operating range of the amplifier.
+
+`gain-flatmax`
+
+:   The optimal operating point of the amplifier.
+This is the place where the gain tilt and the NF of the amplifier are at its best.
+
+`gain-min`
+
+: Minimal possible gain that can be set for the EDFA.
+Any lower gain requires adding a physical attenuator.
+
+`max-power-out`
+
+: Total power cap at the output of the amplifier, measured across the whole spectrum.
+
+`has-output-voa`
+
+: Specifies if there's a Variable Optical Attenuator (VOA) at the EDFA's output port.
+
+One of the key parameters of an amplifier is the method to use for [computing the Noise Figure (NF)](concepts-nf-model).
+Here's how they are represented in YANG data:
+
+(yang-equipment-amplifier-polynomial-NF)=
+#### `polynomial-NF`
+
+The [Polynomial NF model](ext-nf-model-polynomial-NF) requires four coefficients for the polynomial function: `a`, `b`, `c` and `d`.
+
+```json
+{
+  "type": "Juniper-BoosterHG",
+  "gain-min": "10",
+  "gain-flatmax": "25",
+  "max-power-out": "21",
+  "frequency-min": "191.35",
+  "frequency-max": "196.1",
+  "polynomial-NF": {
+    "a": "0.0008",
+    "b": "0.0272",
+    "c": "-0.2249",
+    "d": "6.4902"
+  }
+}
+```
+
+(yang-equipment-amplifier-min-max-NF)=
+#### `min-max-NF`
+
+This is an operator-focused model.
+Performance is defined by the [minimal and maximal NF](nf-model-min-max-NF).
+
+`nf-min`
+
+: Minimal Noise Figure.
+This is achieved when the EDFA operates at its maximal flat gain (see the `gain-flatmax` parameter).
+
+`nf-max`
+
+: Maximal Noise Figure.
+This worst-case scenario applies when the EDFA operates at its minimal gain (see the `gain-min` parameter).
+
+(yang-equipment-amplifier-openroadm)=
+#### OpenROADM
+
+NF models for preamps, boosters and inline amplifiers as defined via the OpenROADM group.
+
+(yang-equipment-amplifier-polynomial-OSNR-OpenROADM)=
+##### `OpenROADM-ILA`
+
+This model is useful for [amplifiers compliant to the OpenROADM specification for ILA](ext-nf-model-polynomial-OSNR-OpenROADM).
+The input parameters to this model are once again four coefficients `a`. `b`, `c` and `d`:
+
+```json
+{
+  "type": "low-noise",
+  "gain-min": "12",
+  "gain-flatmax": "27",
+  "max-power-out": "22",
+  "frequency-min": "191.35",
+  "frequency-max": "196.1",
+  "OpenROADM-ILA": {
+    "a": "-8.104e-4",
+    "b": "-6.221e-2",
+    "c": "-5.889e-1",
+    "d": "37.62",
+  }
+}
+```
+
+(yang-equipment-amplifier-OpenROADM-preamp-booster)=
+##### `OpenROADM-preamp` and `OpenROADM-booster`
+
+No extra parameters are defined for these NF models.
+See the [model documentation](ext-nf-model-noise-mask-OpenROADM) for details.
+
+(yang-equipment-amplifier-composite)=
+#### `composite`
+
+A [composite](ext-nf-model-dual-stage-amplifier) amplifier combines two distinct amplifiers.
+The first amplifier will be always operated at its maximal gain (and therefore its best NF).
+
+`preamp`
+
+: Reference to the first amplifier model
+
+`booster`
+
+: Reference to the second amplifier model
+
+(yang-equipment-amplifier-raman-approximation)=
+#### `raman-approximation`
+
+A fixed-NF amplifier, especially suitable for emulating Raman amplifiers
+in scenarios where the Raman-aware engine cannot be used.
+
+`nf`
+
+: Noise Figure of the amplifier.
+
+(yang-equipment-amplifier-fine-tuning)=
+#### Advanced EDFA parameters
+
+In addition to all parameters specified above, it is also possible to describe the EDFA\'s performance in higher detail.
+All of the following parameters are given as measurement points at arbitrary frequencies.
+The more data points provided, the more accurate is the simulation.
+The underlying model uses piecewise linear approximation to estimate values which are laying in between the provided values.
+
+`dynamic-gain-tilt`
+
+: FIXME: document this
+
+`gain-ripple`
+
+: Difference of the amplifier gain for a specified frequency, as compared to the typical gain over the whole spectrum
+
+`nf-ripple`
+
+: Difference in the resulting Noise Figure (NF) as a function of a carrier frequency
+
+```json
+{
+  "type": "vg-15-26",
+  "gain-min": "15",
+  "gain-flatmax": "26",
+  "dynamic-gain-tilt": [
+    {
+      "frequency": "191.35",
+      "dynamic-gain-tilt": "0"
+    },
+    {
+      "frequency": "196.1",
+      "dynamic-gain-tilt": "2.4"
+    }
+  ],
+  "max-power-out": "23",
+  "min-max-NF": {
+    "nf-min": "6.0",
+    "nf-max": "10.0"
+  }
+}
+```
+
+These values are optional. If not provided, gain and NF is assumed to not vary with carrier frequency.
+
+(yang-equipment-fiber)=
+### Fiber
+
+An optical fiber attenuates the signal and acts as a medium for non-linear interference (NLI) for all signals in the propagated spectrum.
+When using the Raman-aware simulation engine, the Raman effect is also considered.
+
+`type`
+
+: A free-form name which must be unique within the whole equipment library, such as `G.652`.
+
+`chromatic-dispersion`
+
+: Chromatic dispersion, in $\frac{ps}{nm\times km}$.
+
+`chromatic-dispersion-slope`
+
+: Dispersion slope is related to the $\beta _3$ coefficient.
+In $\frac{ps}{nm^{2}\times km}$.
+
+`gamma`
+
+: Fiber\'s $\gamma$ coefficient.
+In $\frac{1}{W\times km}$.
+
+`pmd-coefficient`
+
+: Coefficient for the Polarization Mode Dispersion (PMD).
+In $\frac{ps}{\sqrt{km}}$.
+
+`raman-efficiency`
+
+: Normalized efficiency of the Raman amplification per operating frequency.
+This is a required parameter if using Rama-aware simulation engine.
+The data type is a YANG list keyed by `delta-frequency` (in $\text{THz}$). 
+For each `delta-frequency`, provide the `cr` parameter which is a dimensionless number indicating how effective the Raman transfer of energy is at that particular frequency offset from the pumping signal.
+
+```javascript
+{
+  "type": "SSMF",
+  "dispersion": "16.7",
+  "gamma": "1.27",
+  "pmd-coefficient": "0.0400028124",
+  "raman-efficiency": [
+    {
+      "delta-frequency": "0",
+      "cr": "0"
+    },
+    {
+      "delta-frequency": "0.5",
+      "cr": "9.4e-06"
+    },
+
+    // more frequencies go here
+
+    {
+      "delta-frequency": "42.0",
+      "cr": "1e-07"
+    }
+  ]
+}
+```
+(yang-equipment-roadm)=
+### ROADMs
+
+Compared to EDFAs and fibers, ROADM descriptions are simpler. 
+In GNPy, ROADM mainly acts as a smart, spectrum-specific attenuator which equalizes carrier power to a specified power level. 
+The PMD contribution is also taken into account, and the Add and Drop stages affect signal\'s OSNR as well.
+
+`type`
+
+: Unique model identification, used when cross-referencing from the network topology.
+
+`add-drop-osnr`
+
+: OSNR penalty introduced by the Add stage or the Drop stage of this ROADM type.
+
+`target-channel-out-power`
+
+: Per-channel target TX power towards the egress amplifier.
+Within GNPy, a ROADM is expected to attenuate any signal that enters the ROADM node to this level. 
+This can be overridden on a per-link in the network topology.
+
+`pmd`
+
+: Polarization mode dispersion (PMD) penalty of the express path within this ROADM model. 
+In $\text{s}$.
+
+`compatible-preamp` and `compatible-booster`
+
+: List of all allowed booster/preamplifier types. 
+Useful for specifying constraints on what amplifier modules fit into ROADM chassis, and when using fully disaggregated ROADM topologies as well.
+
+(yang-equipment-transponder)=
+### Transponders
+
+Transponders (or transceivers) are sources and detectors of optical signals.
+There are a few parameters which apply to a transponder model:
+
+`type`
+
+: Unique name, for corss-referencing from the topology data.
+
+`frequency-min` and `frequency-max`
+
+: Minimal and maximal operating frequencies of the receiver and transmitter.
+
+A lot of transponders can operate in a variety of modes, which are described via the `transceiver/mode` list:
+
+`name`
+
+: Identification of the transmission mode. 
+Free form, has to be unique within one transponder type.
+
+`bit-rate`
+
+: Data bit rate, in $\text{Gbits}\times s^{-1}$.
+
+`baud-rate`
+
+: Symbol modulation rate, in $\text{Gbaud}$.
+
+`required-osnr`
+
+: Minimal allowed OSNR for the receiver.
+
+`in-band-tx-osnr`
+
+: Worst-case guaranteed initial OSNR at the Tx port per 0.1nm of bandwidth
+Only the in-band OSNR is considered.
+
+`grid-spacing`
+
+: Minimal grid spacing, i.e., an effective channel spectral bandwidth.
+In $\text{Hz}$.
+
+`tx-roll-off`
+
+: Roll-off parameter ($\beta$) of the TX pulse shaping filter.
+This assumes a raised-cosine filter.
diff --git a/gnpy/yang/tip/tip-photonic-equipment.yang b/gnpy/yang/tip/tip-photonic-equipment.yang
new file mode 100644
index 00000000..55c9117c
--- /dev/null
+++ b/gnpy/yang/tip/tip-photonic-equipment.yang
@@ -0,0 +1,685 @@
+module tip-photonic-equipment {
+  yang-version 1.1;
+  namespace "https://oopt.telecominfraproject.com/yang/equipment";
+  prefix "tip-pe";
+
+  organization "Telecom Infrastructure Project";
+  contact "https://github.com/Telecominfraproject/oopt-gnpy";
+  description "Catalog of photonic equipment for simulating signal propagation via the OOPT-PSE GNPy tool";
+
+  revision 2020-09-01 {
+    description "Initial release";
+    reference "Internal documentation";
+  }
+
+  typedef db-ratio {
+    type decimal64 {
+      fraction-digits 2;
+    }
+    units "dB";
+    description "Decibels";
+  }
+
+  typedef noise-figure {
+    type db-ratio {
+      range "3.0 .. 20.0";
+    }
+    description "Noise Figure of an amplifier";
+  }
+
+  typedef gain {
+    type db-ratio {
+      range "0 .. 40.0";
+    }
+    description "Gain of an amplifier";
+  }
+
+  typedef power {
+    type decimal64 {
+      fraction-digits 2;
+      range "-99.9 .. 30.0";
+    }
+    units "dBm";
+    description "Optical power in dBm";
+  }
+
+  typedef carrier-frequency {
+    type decimal64 {
+      fraction-digits 7;
+      range "191.0 .. 197.0";
+    }
+    units "THz";
+    description "Optical frequency of a signal";
+  }
+
+  typedef frequency-channel-spacing {
+    type decimal64 {
+      fraction-digits 7;
+      range "6.25 .. 200.0";
+    }
+    units "GHz";
+    description "Channel spacing";
+  }
+
+  typedef baud-rate {
+    type decimal64 {
+      fraction-digits 4;
+      range "10 .. 130";
+    }
+    units "Gbaud";
+    description "Symbol rate";
+  }
+
+  typedef roll-off {
+    type decimal64 {
+      fraction-digits 4;
+      range "0 .. 1";
+    }
+    description "Roll-off parameter (β) of the TX pulse shaping filter. This assumes a raised-cosine filter.";
+  }
+
+  typedef cd {
+    type decimal64 {
+      fraction-digits 2;
+      range "-50000 .. 50000";
+    }
+    units "ps × nm⁻¹";
+    description "Chromatic Dispersion (CD).";
+  }
+
+  typedef pmd {
+    type decimal64 {
+      fraction-digits 4;
+    }
+    units "ps";
+    description "Polarization mode dispersion (PMD).";
+  }
+
+  typedef polynomial-coefficient {
+    type decimal64 {
+      fraction-digits 12;
+    }
+    description "One coefficient within a polynomial";
+  }
+
+  grouping cubic-polynomial-coefficients {
+    description "Coefficients for a polynomial of a third degree: f(x) = a*x³ + b*x² + c*x + d";
+    leaf a {
+      type polynomial-coefficient;
+      mandatory true;
+      description "Cubic (x³) coefficient";
+    }
+    leaf b {
+      type polynomial-coefficient;
+      mandatory true;
+      description "Quadratic (x²) coefficient";
+    }
+    leaf c {
+      type polynomial-coefficient;
+      mandatory true;
+      description "Linear (x) coefficient";
+    }
+    leaf d {
+      type polynomial-coefficient;
+      mandatory true;
+      description "Offset (+) coefficient";
+    }
+  }
+
+  grouping amp-spectrum-profile {
+    description "Changes in amplifier's operation as a function of frequency";
+
+    list gain-ripple {
+      leaf frequency {
+        type carrier-frequency;
+        description "Frequency for the specific gain ripple deviation";
+      }
+
+      leaf gain-ripple {
+        type db-ratio;
+        mandatory true;
+        description "Gain ripple deviation at a given frequency";
+      }
+
+      key "frequency";
+
+      description "Amplifier gain ripple excursion comb list in dB across the frequency range";
+    }
+
+    list nf-ripple {
+      leaf frequency {
+        type carrier-frequency;
+        description "Frequency for the specific NF ripple deviation";
+      }
+
+      leaf nf-ripple {
+        type db-ratio;
+        mandatory true;
+        description "NF ripple deviation at a given frequency";
+      }
+
+      key "frequency";
+
+      description "Amplifier NF ripple excursion comb list in dB across the frequency range";
+    }
+
+    list dynamic-gain-tilt {
+      leaf frequency {
+        type carrier-frequency;
+        description "Frequency for the specific NF ripple deviation";
+      }
+
+      leaf dynamic-gain-tilt {
+        type db-ratio;
+        mandatory true;
+        description "DGT at a specified frequency";
+      }
+
+      key "frequency";
+
+      description "Dynamic Gain Tilt (DGT) refers to a relative change of gain
+      at a given frequency when compared to a reference frequency.
+
+      Intro about the model: https://telecominfraproject.workplace.com/groups/OOPT.PSE/permalink/957144244450445/
+      Relevant paper: https://www.osapublishing.org/jlt/abstract.cfm?uri=JLT-18-3-343";
+    }
+  }
+
+  grouping amp-common {
+    description "Properties common to all EDFAs except the composite models";
+
+    leaf frequency-min {
+      type carrier-frequency;
+      default 191.325;
+      description "Minimal frequency supported by this amplifier
+
+      This refers to the edge of the optical spectrum, not to a central frequency of a fixed grid.";
+    }
+
+    leaf frequency-max {
+      type carrier-frequency;
+      default 196.125;
+      description "Maximal frequency supported by this amplifier
+
+      This refers to the edge of the optical spectrum, not to a central frequency of a fixed grid.";
+    }
+
+    leaf has-output-voa {
+      type boolean;
+      default false;
+      description "If true, output VOA is present.
+
+      An amplifier with an output VOA can be pushed to operate at its the max-power-out if the output VOA is available.";
+    }
+
+    leaf gain-flatmax {
+      type gain;
+      mandatory true;
+      description "Maximal gain of the nominal range (without entering the extended range)
+
+      Once the amplifier's gain gets pushed into the extended range, it begins to tilt as specified in the dynamic-gain-tilt.";
+    }
+
+    leaf max-power-out {
+      type power;
+      mandatory true;
+      description "Maximal output power at the amplifier's output port
+
+      The total signal output power will not be allowed beyond this value.";
+    }
+  }
+
+
+  list amplifier {
+    key "type";
+    description "Available amplifier (EDFA) models";
+
+    leaf type {
+      type string;
+      description "Brief identification of the amplifier model. This is used for cross-referencing from topology data.";
+    }
+
+    uses amp-common {
+      when "count(composite) = 0";
+      description "Common parameters for all EDFAs except aggregated ones";
+    }
+
+    leaf gain-min {
+      type gain;
+      mandatory true;
+      description "Minimal possible gain of the amplifier
+
+      If the amplifier's gain is set below this value, the amplifier's input is automatically padded with an attenuator,
+      and the NF is increased by the attenuation of this padding.";
+    }
+
+    choice noise-model {
+      mandatory true;
+      description "What simulation algorithm to use for this amplifier model";
+
+      case polynomial-NF {
+        container polynomial-NF {
+          description "Whitebox model with detailed information about gain ripple, NF ripple and dynamic gain tilt
+
+          Polynomial coefficients for NF calculation:
+
+            f(x) = a*x³ + b*x² + c*x + d
+
+            NF = f(gain_max - gain)
+
+          This model can be also used for fixed-gain fixed-NF amplifiers. In that case, use:
+
+            a = b = c = 0
+            d = NF";
+
+          uses cubic-polynomial-coefficients;
+        }
+      }
+
+      case min-max-NF {
+        container min-max-NF {
+          description "Operator-focused model
+
+          Performance is defined by the minimal and maximal NF. These are especially suited to model a dual-coil
+          EDFA with a VOA in between.";
+
+          leaf nf-min {
+            type noise-figure;
+            mandatory true;
+            description "Minimal Noise Figure (operating at the point of the maximal flat gain)
+
+            See gain-flatmax.";
+          }
+
+          leaf nf-max {
+            type noise-figure;
+            mandatory true;
+            description "Maximal Noise Figure (operating at the minimal gain)";
+          }
+        }
+      }
+
+      case OpenROADM-ILA {
+        container OpenROADM-ILA {
+          description "EDFA model based on the OpenROADM specification for an ILA
+
+          OpenROADM describes amplifier performance in terms of an incremental OSNR as a function of input power:
+
+            Incremental OSNR = a*Pᵢₙ³ + b*Pᵢₙ² + c*Pᵢₙ + d
+          ";
+
+          uses cubic-polynomial-coefficients;
+        }
+      }
+
+      case OpenROADM-preamp {
+        container OpenROADM-preamp {
+          presence true;
+          description "Linear impairments of the MW-MW path within an OpenROADM ROADM node
+
+          Unlike GNPy which simulates the preamplifier and the booster separately as two amplifiers for best accuracy,
+          the OpenROADM specification mandates a certain performance level for a combination of these two amplifiers.
+          For the express path, the effective noise mask comprises the preamplifier and the booster.
+          When terminating a channel, the same effective noise mask is mandated for a combination of the preamplifier
+          and the drop stage.
+
+          This NF model provides all of the linear impairments to the signal, including those which are incurred by
+          the booster in a real network.";
+        }
+      }
+
+      case OpenROADM-booster {
+        container OpenROADM-booster {
+          presence true;
+          description "A faux, \"zero-noise\" amplifier for use along with OpenROADM-preamp as a booster.";
+        }
+      }
+
+      case composite {
+        container composite {
+          description "Dual-stage amplifier combines two distinct amplifiers
+
+          The first amplifier will be always operated at its maximal gain (and therefore its best NF).";
+
+          leaf preamp {
+            type leafref {
+              path "/tip-pe:amplifier/type";
+            }
+            must "count(deref(.)/../composite) = 0" {
+              error-message "First (preamp) stage of a composite amplifier cannot be a composite amplifier";
+            }
+            must "../../gain-min >= deref(.)/../gain-min" {
+              error-message "Minimal total gain of a composite EDFA cannot be lower that the minimal gain of the preamp";
+            }
+            mandatory true;
+            description "Amplifier type used as a preamplifier, i.e., the first stage";
+          }
+
+          leaf booster {
+            type leafref {
+              path "/tip-pe:amplifier/type";
+            }
+            must "count(deref(.)/../composite) = 0" {
+              error-message "Second (booster) stage of a composite amplifier cannot be a composite amplifier";
+            }
+            must "(deref(.)/../frequency-min <= deref(../preamp)/../frequency-max) and
+                  (deref(.)/../frequency-max >= deref(../preamp)/../frequency-min)" {
+              error-message "booster/preamp operating frequencies do not overlap";
+            }
+            mandatory true;
+            description "Amplifier type used as a booster, i.e., the second stage";
+          }
+        }
+      }
+
+      case raman-approximation {
+        container raman-approximation {
+          description "Emulate a Raman amplifier with a possibly negative NF
+
+          This NF model assumes a particular, fixed NF. It is similar to the polynomial-NF model, except that the
+          effective NF value is fixed (and therefore it does not vary with the amplifier's operating point), and
+          that the effective NF can be described as a negative value.
+
+          Use this for model to (roughly) emulate a Raman amplifier when the detailed description of Raman pumps
+          is not available from the equipment vendor.";
+
+          leaf nf {
+            type db-ratio {
+              range "-5.0 .. 20.0";
+            }
+            mandatory true;
+            description "Noise Figure (NF) of the amplifier";
+          }
+        }
+      }
+    }
+
+    uses amp-spectrum-profile {
+      when "count(deref(.)/composite) = 0";
+    }
+
+    leaf model-precision {
+      type enumeration {
+        enum public-approximation {
+          description "These data come from a publicly available datasheet, and as such might be only an approximate representation";
+        }
+        enum reasonably-precise {
+          description "The GNPy team believes that these are reasonably accurate";
+        }
+      }
+      default reasonably-precise;
+      description "How precise are the modeling data
+
+      If a simulation runs with only approximate inputs, the simulation results might be \"tainted\" with inaccuracies.";
+    }
+  }
+
+
+  list fiber {
+    key "type";
+    description "Available fiber types";
+
+    leaf type {
+      type string;
+      description "Unique identification of the fiber type. This is used for cross-referencing from topology data.";
+    }
+
+    leaf chromatic-dispersion {
+      type decimal64 {
+        fraction-digits 6;
+        range "-25 .. 25";
+      }
+      units "ps × nm⁻¹ × km⁻¹";
+      mandatory true;
+      description "Chromatic dispersion";
+    }
+
+    leaf chromatic-dispersion-slope {
+      type decimal64 {
+        fraction-digits 8;
+        range "0 .. 0.1";
+      }
+      units "ps × nm⁻² × km⁻¹";
+      default "0.07";
+      description "Chromatic dispersion slope is related to the β₃ coefficient
+
+      Cf. Abramczyk, Halina. Dispersion phenomena in optical fibers. Virtual European University on Lasers, 2005.
+
+      http://mitr.p.lodz.pl/evu/lectures/Abramczyk3.pdf";
+    }
+
+    leaf gamma {
+      type decimal64 {
+        fraction-digits 8;
+        range "0.5 .. 2.5";
+      }
+      units "W⁻¹ × km⁻¹";
+      mandatory true;
+      description "Fiber's γ coefficient
+
+      See, e.g., A. Carena, G. Bosco, V. Curri, P. Poggiolini, M. Tapia Taiba, and F. Forghieri. Statistical characterization
+      of PM-QPSK signals after propagation in uncompensated fiber links. In European Conference on Optical Communications,
+      2010, 1–3. IEEE, 2010-09.
+
+      URL: http://ieeexplore.ieee.org/document/5621509/
+      doi:10.1109/ECOC.2010.5621509";
+    }
+
+    leaf pmd-coefficient {
+      type decimal64 {
+        fraction-digits 10;
+        range "0 .. 10";
+      }
+      units "ps × √(km)⁻¹";
+      mandatory true;
+      description "Polarization mode dispersion (PMD) coefficient";
+    }
+
+    list raman-efficiency {
+        key "delta-frequency";
+        description "Efficiency of Raman amplification in the fiber medium per operating frequency
+
+        See, e.g., J. Bromage. Raman Amplification for Fiber Communications Systems. In J. Lightwave Technol.  22, 79- (2004).";
+
+        leaf delta-frequency {
+          type decimal64 {
+            fraction-digits 3;
+            range "0 .. 60";
+          }
+          units "THz";
+          description "Spectral difference between the pumping photon and the one receiving energy";
+        }
+
+        leaf cr {
+          type decimal64 {
+            fraction-digits 12;
+            range "0 .. 1";
+          }
+          mandatory true;
+          description "Normalized Raman efficiency (the Cᵣ parameter)";
+        }
+    }
+  }
+
+
+  list transceiver {
+    key "type";
+    description "Available transceivers";
+
+    leaf type {
+      type string;
+      description "Unique identification of the transceiver type. This is used for cross-referencing from topology data.";
+    }
+
+    leaf frequency-min {
+      type carrier-frequency;
+      default 191.35;
+      description "Minimal frequency supported by this transceiver model";
+    }
+
+    leaf frequency-max {
+      type carrier-frequency;
+      default 196.1;
+      description "Maximal frequency supported by this transceiver model";
+    }
+
+    list mode {
+      key "name";
+      min-elements 1;
+      description "Operating mode of a transceiver";
+
+      leaf name {
+        type string;
+        description "Name of this operating mode";
+      }
+
+      leaf bit-rate {
+        type uint16 {
+          range "100 .. 1000";
+        }
+        units "Gbits * s⁻¹";
+        description "Data bit rate";
+      }
+
+      leaf baud-rate {
+        type baud-rate;
+        mandatory true;
+        description "Symbol baud rate";
+      }
+
+      leaf required-osnr {
+        type db-ratio {
+          range "10..40";
+        }
+        mandatory true;
+        description "Minimal required OSNR at the Rx port per 0.1nm of bandwidth";
+      }
+
+      leaf in-band-tx-osnr {
+        type db-ratio;
+        mandatory true;
+        description "Worst-case guaranteed initial OSNR at the Tx port per 0.1nm of bandwidth
+
+        Only the in-band OSNR is considered.";
+      }
+
+      leaf grid-spacing {
+        type frequency-channel-spacing;
+        mandatory true;
+        description "Minimal grid spacing
+
+        This includes the effective channel spectral bandwidth as well as any operational constraints and policies.";
+      }
+
+      leaf tx-roll-off {
+        type roll-off;
+        mandatory true;
+        description "Roll-off parameter (β) of the TX pulse shaping filter. This assumes a raised-cosine filter.";
+      }
+
+      leaf max-chromatic-dispersion {
+        type cd;
+        description "Maximal allowed CD (a hard limit)";
+      }
+
+      leaf max-polarization-mode-dispersion {
+        type pmd {
+          range "0 .. 500";
+        }
+        description "Maximal allowed PMD (a hard limit)";
+      }
+
+      list chromatic-and-polarization-dispersion-penalty {
+        key "chromatic-dispersion  polarization-mode-dispersion";
+
+        leaf chromatic-dispersion {
+          type cd;
+          must ". <= ../../max-chromatic-dispersion" {
+            error-message "CD in the penalty matrix exceeds receiver tolerance";
+          }
+          description "CD for a given penalty";
+        }
+
+        leaf polarization-mode-dispersion {
+          type pmd {
+            range "0 .. 500";
+          }
+          must ". <= ../../max-polarization-mode-dispersion" {
+            error-message "PMD in the penalty matrix exceeds receiver tolerance";
+          }
+          description "PMD for a given penalty";
+        }
+
+        leaf penalty {
+          type db-ratio {
+            range "-5 .. 10";
+          }
+          mandatory true;
+          description "Resulting GSNR penalty at the specified CD and PMD";
+        }
+
+        description "GSNR penalty for a combination of a CD and PMD
+
+        The receiver performance should be de-rated by a given `penalty` for a specified combination of CD and PMD.
+        GNPy will use linear approximation between the provided datapoints in the CD/PMD matrix.
+        ";
+      }
+    }
+  }
+
+
+  list roadm {
+    key "type";
+    description "ROADM - Reconfigurable Optical Add/Drop Multiplexer";
+
+    leaf type {
+      type string;
+      description "Unique identification of the transponder type. This is used for cross-referencing from topology data.";
+    }
+
+    leaf add-drop-osnr {
+      type db-ratio;
+      mandatory true;
+      description "OSNR penalty introduced by the Add stage and the Drop stage of this ROADM model
+
+      Effective degradation of the signal, taking into account both the Add and the Drop stages of this ROADM model.";
+    }
+
+    leaf target-channel-out-power {
+      type power;
+      mandatory true;
+      description "Per-channel target TX power towards the egress amplifier
+
+      Within GNPy, a ROADM is expected to attenuate any signal that enters the ROADM node to this level. This can be
+      overridden on a per-link basis in the network topology.";
+    }
+
+    leaf polarization-mode-dispersion {
+      type pmd {
+        range "0 .. 5";
+      }
+      mandatory true;
+      description "Polarization mode dispersion (PMD) penalty of the express path within this ROADM model";
+    }
+
+    leaf-list compatible-preamp {
+      type leafref {
+        path "/tip-pe:amplifier/type";
+      }
+      description "A set of allowed amplifier types to be used in the ingress direction
+
+      If empty, autodesign is allowed to pick any amplifier as a preamp.";
+    }
+
+    leaf-list compatible-booster {
+      type leafref {
+        path "/tip-pe:amplifier/type";
+      }
+      description "A set of allowed amplifier types to be used in the egress direction
+
+      If empty, autodesign is allowed to pick any amplifier as a booster.";
+    }
+
+  }
+
+}
diff --git a/gnpy/yang/yanglib.json b/gnpy/yang/yanglib.json
index 73799640..02c167be 100644
--- a/gnpy/yang/yanglib.json
+++ b/gnpy/yang/yanglib.json
@@ -25,6 +25,12 @@
         "revision": "2018-02-26",
         "namespace": "urn:ietf:params:xml:ns:yang:ietf-network",
         "conformance-type": "implement"
+      },
+      {
+        "name": "tip-photonic-equipment",
+        "revision": "2020-09-01",
+        "namespace": "https://oopt.telecominfraproject.com/yang/equipment",
+        "conformance-type": "implement"
       }
     ]
   }
diff --git a/tests/yang/01-dummy.json b/tests/yang/01-dummy.json
new file mode 100644
index 00000000..eeb2e806
--- /dev/null
+++ b/tests/yang/01-dummy.json
@@ -0,0 +1,486 @@
+{
+  "tip-photonic-equipment:amplifier": [
+    {
+      "type": "fixed-27",
+      "gain-min": "27",
+      "gain-flatmax": "27",
+      "max-power-out": "21.9",
+      "polynomial-NF": {
+        "a": "0",
+        "b": "0",
+        "c": "0",
+        "d": "4.9"
+      }
+    },
+    {
+      "type": "fixed-22",
+      "gain-min": "22",
+      "gain-flatmax": "22",
+      "max-power-out": "21.9",
+      "polynomial-NF": {
+        "a": "0",
+        "b": "0",
+        "c": "0",
+        "d": "4.8"
+      }
+    },
+    {
+      "type": "vg-15-30",
+      "gain-min": "15",
+      "gain-flatmax": "26",
+      "dynamic-gain-tilt": [
+        {
+          "frequency": "191.35",
+          "dynamic-gain-tilt": "0"
+        },
+        {
+          "frequency": "196.1",
+          "dynamic-gain-tilt": "2.4"
+        }
+      ],
+      "max-power-out": "23",
+      "min-max-NF": {
+        "nf-min": "6.0",
+        "nf-max": "10.0"
+      }
+    },
+    {
+      "type": "vg-8-16",
+      "gain-min": "8",
+      "gain-flatmax": "15",
+      "max-power-out": "23",
+      "min-max-NF": {
+        "nf-min": "6.5",
+        "nf-max": "11.0"
+      }
+    },
+    {
+      "type": "dual--vg-15-30--vg-8-16",
+      "gain-min": "25.0",
+      "composite": {
+        "preamp": "vg-15-30",
+        "booster": "vg-8-16"
+      }
+    },
+    {
+      "type": "Juniper-BoosterHG",
+      "gain-min": "10",
+      "gain-flatmax": "25",
+      "max-power-out": "21",
+      "frequency-min": "191.35",
+      "frequency-max": "196.1",
+      "polynomial-NF": {
+        "a": "0.0008",
+        "b": "0.0272",
+        "c": "-0.2249",
+        "d": "6.4902"
+      }
+    }
+  ],
+  "tip-photonic-equipment:fiber": [
+    {
+      "type": "SSMF",
+      "chromatic-dispersion": "16.7",
+      "gamma": "1.27",
+      "pmd-coefficient": "0.0400028124",
+      "raman-efficiency": [
+        {
+          "delta-frequency": "0.0",
+          "cr": "0"
+        },
+        {
+          "delta-frequency": "0.5",
+          "cr": "9.4e-06"
+        },
+        {
+          "delta-frequency": "1.0",
+          "cr": "2.92e-05"
+        },
+        {
+          "delta-frequency": "1.5",
+          "cr": "4.88e-05"
+        },
+        {
+          "delta-frequency": "2.0",
+          "cr": "6.82e-05"
+        },
+        {
+          "delta-frequency": "2.5",
+          "cr": "8.31e-05"
+        },
+        {
+          "delta-frequency": "3.0",
+          "cr": "9.4e-05"
+        },
+        {
+          "delta-frequency": "3.5",
+          "cr": "0.0001014"
+        },
+        {
+          "delta-frequency": "4.0",
+          "cr": "0.0001069"
+        },
+        {
+          "delta-frequency": "4.5",
+          "cr": "0.0001119"
+        },
+        {
+          "delta-frequency": "5.0",
+          "cr": "0.0001217"
+        },
+        {
+          "delta-frequency": "5.5",
+          "cr": "0.0001268"
+        },
+        {
+          "delta-frequency": "6.0",
+          "cr": "0.0001365"
+        },
+        {
+          "delta-frequency": "6.5",
+          "cr": "0.000149"
+        },
+        {
+          "delta-frequency": "7.0",
+          "cr": "0.000165"
+        },
+        {
+          "delta-frequency": "7.5",
+          "cr": "0.000181"
+        },
+        {
+          "delta-frequency": "8.0",
+          "cr": "0.0001977"
+        },
+        {
+          "delta-frequency": "8.5",
+          "cr": "0.0002192"
+        },
+        {
+          "delta-frequency": "9.0",
+          "cr": "0.0002469"
+        },
+        {
+          "delta-frequency": "9.5",
+          "cr": "0.0002749"
+        },
+        {
+          "delta-frequency": "10.0",
+          "cr": "0.0002999"
+        },
+        {
+          "delta-frequency": "10.5",
+          "cr": "0.0003206"
+        },
+        {
+          "delta-frequency": "11.0",
+          "cr": "0.0003405"
+        },
+        {
+          "delta-frequency": "11.5",
+          "cr": "0.0003592"
+        },
+        {
+          "delta-frequency": "12.0",
+          "cr": "0.000374"
+        },
+        {
+          "delta-frequency": "12.5",
+          "cr": "0.0003826"
+        },
+        {
+          "delta-frequency": "12.75",
+          "cr": "0.0003841"
+        },
+        {
+          "delta-frequency": "13.0",
+          "cr": "0.0003826"
+        },
+        {
+          "delta-frequency": "13.25",
+          "cr": "0.0003802"
+        },
+        {
+          "delta-frequency": "13.5",
+          "cr": "0.0003756"
+        },
+        {
+          "delta-frequency": "14.0",
+          "cr": "0.0003549"
+        },
+        {
+          "delta-frequency": "14.5",
+          "cr": "0.0003795"
+        },
+        {
+          "delta-frequency": "14.75",
+          "cr": "0.000344"
+        },
+        {
+          "delta-frequency": "15.0",
+          "cr": "0.0002933"
+        },
+        {
+          "delta-frequency": "15.5",
+          "cr": "0.0002024"
+        },
+        {
+          "delta-frequency": "16.0",
+          "cr": "0.0001158"
+        },
+        {
+          "delta-frequency": "16.5",
+          "cr": "8.46e-05"
+        },
+        {
+          "delta-frequency": "17.0",
+          "cr": "7.14e-05"
+        },
+        {
+          "delta-frequency": "17.5",
+          "cr": "6.86e-05"
+        },
+        {
+          "delta-frequency": "18.0",
+          "cr": "8.5e-05"
+        },
+        {
+          "delta-frequency": "18.25",
+          "cr": "8.93e-05"
+        },
+        {
+          "delta-frequency": "18.5",
+          "cr": "9.01e-05"
+        },
+        {
+          "delta-frequency": "18.75",
+          "cr": "8.15e-05"
+        },
+        {
+          "delta-frequency": "19.0",
+          "cr": "6.67e-05"
+        },
+        {
+          "delta-frequency": "19.5",
+          "cr": "4.37e-05"
+        },
+        {
+          "delta-frequency": "20.0",
+          "cr": "3.28e-05"
+        },
+        {
+          "delta-frequency": "20.5",
+          "cr": "2.96e-05"
+        },
+        {
+          "delta-frequency": "21.0",
+          "cr": "2.65e-05"
+        },
+        {
+          "delta-frequency": "21.5",
+          "cr": "2.57e-05"
+        },
+        {
+          "delta-frequency": "22.0",
+          "cr": "2.81e-05"
+        },
+        {
+          "delta-frequency": "22.5",
+          "cr": "3.08e-05"
+        },
+        {
+          "delta-frequency": "23.0",
+          "cr": "3.67e-05"
+        },
+        {
+          "delta-frequency": "23.5",
+          "cr": "5.85e-05"
+        },
+        {
+          "delta-frequency": "24.0",
+          "cr": "6.63e-05"
+        },
+        {
+          "delta-frequency": "24.5",
+          "cr": "6.36e-05"
+        },
+        {
+          "delta-frequency": "25.0",
+          "cr": "5.5e-05"
+        },
+        {
+          "delta-frequency": "25.5",
+          "cr": "4.06e-05"
+        },
+        {
+          "delta-frequency": "26.0",
+          "cr": "2.77e-05"
+        },
+        {
+          "delta-frequency": "26.5",
+          "cr": "2.42e-05"
+        },
+        {
+          "delta-frequency": "27.0",
+          "cr": "1.87e-05"
+        },
+        {
+          "delta-frequency": "27.5",
+          "cr": "1.6e-05"
+        },
+        {
+          "delta-frequency": "28.0",
+          "cr": "1.4e-05"
+        },
+        {
+          "delta-frequency": "28.5",
+          "cr": "1.13e-05"
+        },
+        {
+          "delta-frequency": "29.0",
+          "cr": "1.05e-05"
+        },
+        {
+          "delta-frequency": "29.5",
+          "cr": "9.8e-06"
+        },
+        {
+          "delta-frequency": "30.0",
+          "cr": "9.8e-06"
+        },
+        {
+          "delta-frequency": "30.5",
+          "cr": "1.13e-05"
+        },
+        {
+          "delta-frequency": "31.0",
+          "cr": "1.64e-05"
+        },
+        {
+          "delta-frequency": "31.5",
+          "cr": "1.95e-05"
+        },
+        {
+          "delta-frequency": "32.0",
+          "cr": "2.38e-05"
+        },
+        {
+          "delta-frequency": "32.5",
+          "cr": "2.26e-05"
+        },
+        {
+          "delta-frequency": "33.0",
+          "cr": "2.03e-05"
+        },
+        {
+          "delta-frequency": "33.5",
+          "cr": "1.48e-05"
+        },
+        {
+          "delta-frequency": "34.0",
+          "cr": "1.09e-05"
+        },
+        {
+          "delta-frequency": "34.5",
+          "cr": "9.8e-06"
+        },
+        {
+          "delta-frequency": "35.0",
+          "cr": "1.05e-05"
+        },
+        {
+          "delta-frequency": "35.5",
+          "cr": "1.17e-05"
+        },
+        {
+          "delta-frequency": "36.0",
+          "cr": "1.25e-05"
+        },
+        {
+          "delta-frequency": "36.5",
+          "cr": "1.21e-05"
+        },
+        {
+          "delta-frequency": "37.0",
+          "cr": "1.09e-05"
+        },
+        {
+          "delta-frequency": "37.5",
+          "cr": "9.8e-06"
+        },
+        {
+          "delta-frequency": "38.0",
+          "cr": "8.2e-06"
+        },
+        {
+          "delta-frequency": "38.5",
+          "cr": "6.6e-06"
+        },
+        {
+          "delta-frequency": "39.0",
+          "cr": "4.7e-06"
+        },
+        {
+          "delta-frequency": "39.5",
+          "cr": "2.7e-06"
+        },
+        {
+          "delta-frequency": "40.0",
+          "cr": "1.9e-06"
+        },
+        {
+          "delta-frequency": "40.5",
+          "cr": "1.2e-06"
+        },
+        {
+          "delta-frequency": "41.0",
+          "cr": "4e-07"
+        },
+        {
+          "delta-frequency": "41.5",
+          "cr": "2e-07"
+        },
+        {
+          "delta-frequency": "42.0",
+          "cr": "1e-07"
+        }
+      ]
+    },
+    {
+      "type": "NZDF",
+      "chromatic-dispersion": "5.0",
+      "gamma": "1.46",
+      "pmd-coefficient": "0.0400028124"
+    },
+    {
+      "type": "LOF",
+      "chromatic-dispersion": "22",
+      "gamma": "0.843",
+      "pmd-coefficient": "0.0400028124"
+    }
+  ],
+  "tip-photonic-equipment:transceiver": [
+    {
+      "type": "Voyager",
+      "mode": [
+        {
+          "name": "DP-QPSK",
+          "bit-rate": 100,
+          "baud-rate": "32",
+          "required-osnr": "12",
+          "in-band-tx-osnr": "40",
+          "grid-spacing": "37.5",
+          "tx-roll-off": "0.15"
+        }
+      ]
+    }
+  ],
+  "tip-photonic-equipment:roadm": [
+    {
+      "type": "default",
+      "add-drop-osnr": "50.0",
+      "target-channel-out-power": "-20",
+      "polarization-mode-dispersion": "0"
+    }
+  ]
+}