{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.medium-dependent-interface","code":"thing-q1421871","url":"https://ver.cy/models/thing/q1421871/","name":"medium dependent interface","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Information and virtual systems","entryKind":"thing","plane":"INF","domain":["INF.KNW"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A medium dependent interface (MDI) is the interface between an Ethernet physical-layer device and its transmission medium, with characteristics specified for the particular Ethernet physical-layer type.","purpose":"Enable an agent to identify a medium dependent interface, assess its compatibility with a transmission medium and peer interface, and determine which connection, configuration, or verification actions are justified.","scope":{"in":["Identification of the Ethernet PHY type, governing specification, and medium-facing interface boundary","Mechanical mating requirements and contact, pair, lane, or fiber assignments","Applicable electrical or optical signal requirements at the MDI reference plane","Media attachment compatibility, including crossover behavior where applicable","Conditional power delivery requirements at the same attachment boundary","Evidence supporting interface conformance and permitted connection or configuration actions"],"out":["MAC framing, switching, routing, and application protocols","Media independent interfaces between MAC and PHY, such as MII and GMII","Internal PHY coding, signal processing, and implementation architecture","Complete cable or fiber plant design and installation","Connector products considered independently of their Ethernet interface assignment","Complete powered-device or power-sourcing-equipment design"],"boundaries":[]},"distinguishingFeatures":["The boundary faces the transmission medium; a MAC-facing digital interface belongs to an MII-family model instead.","Identification requires a PHY-specific attachment contract; connector appearance alone cannot establish that two MDIs are compatible.","Electrical or optical requirements are assessed at an identified medium-facing reference plane, rather than at arbitrary internal PHY nodes.","An MDI-X designation describes a crossover arrangement within applicable interfaces, rather than a separate networking layer.","The entry represents an interface concept and its requirements; a cable, PHY chip, or connector is a related implementing object."],"structure":{"bundles":[{"id":"mdi-identity-and-contract","name":"MDI identity and contract","description":"Establishes what boundary is being modeled and which Ethernet requirements govern it.","layers":[{"id":"medium-facing-boundary","name":"Medium-facing boundary","description":"Locates the interface relative to the PHY or MAU and the transmission medium.","findings":[{"id":"boundary-identification","name":"Boundary identification","description":"Record the implementing objects on either side and the exact interface boundary, distinguishing the MDI from internal and MAC-facing interfaces.","questions":[{"text":"Where does the specified PHY or MAU meet the transmission medium?","id":"boundary-identification-q01","kind":"definition"},{"text":"Which nearby connector, PHY sublayer, or MII-family interface could be mistaken for this boundary?","id":"boundary-identification-q02","kind":"boundary"}]}]},{"id":"governing-phy-profile","name":"Governing PHY profile","description":"Connects the interface to a versioned set of requirements.","findings":[{"id":"profile-and-revision","name":"Profile and revision","description":"Record the PHY designation and controlling clauses before assigning interface limits or declaring compatibility.","questions":[{"text":"Which standard edition, PHY clauses, amendments, and corrigenda define this MDI?","id":"profile-and-revision-q01","kind":"provenance"},{"text":"Which supported modes share this attachment, and which require a different MDI profile?","id":"profile-and-revision-q02","kind":"boundary"}]}]}]},{"id":"medium-attachment-and-mapping","name":"Medium attachment and mapping","description":"Captures how the medium mates with the interface and how signal paths are assigned.","layers":[{"id":"mechanical-mating","name":"Mechanical mating","description":"Identifies the attachment geometry and supported medium termination.","findings":[{"id":"attachment-compatibility","name":"Attachment compatibility","description":"Record the specified attachment, keying, and termination requirements rather than inferring compatibility from a familiar connector shell.","questions":[{"text":"Which connector or attachment specification and mating geometry apply?","id":"attachment-compatibility-q01","kind":"definition"},{"text":"Does the proposed medium termination satisfy the required mating and keying constraints?","id":"attachment-compatibility-q02","kind":"action"}]}]},{"id":"signal-path-mapping","name":"Signal-path mapping","description":"Describes contact, pair, lane, or fiber roles and applicable remapping behavior.","findings":[{"id":"mapping-and-crossover","name":"Mapping and crossover","description":"Record path assignments and determine whether fixed crossover, automatic crossover, or polarity handling applies to this PHY.","questions":[{"text":"How are contacts, pairs, lanes, or fibers assigned to the signal roles required by this PHY?","id":"mapping-and-crossover-q01","kind":"definition"},{"text":"Which documented crossover or polarity behavior must be considered when selecting or troubleshooting the connection?","id":"mapping-and-crossover-q02","kind":"action"}]}]}]},{"id":"signal-and-power-envelope","name":"Signal and power envelope","description":"Defines the profile-specific conditions under which signals and optional power cross the interface.","layers":[{"id":"electrical-or-optical-envelope","name":"Electrical or optical envelope","description":"Selects the relevant signal quantities and their specified limits.","findings":[{"id":"signal-limits-at-mdi","name":"Signal limits at the MDI","description":"Record only the electrical or optical requirements applicable to the selected profile, including measurement conditions and reference planes.","questions":[{"text":"Which electrical or optical quantities and limit curves apply at this MDI reference plane?","id":"signal-limits-at-mdi-q01","kind":"measurement"},{"text":"Which test conditions and calibration or de-embedding procedures make the measured values comparable to those limits?","id":"signal-limits-at-mdi-q02","kind":"measurement"}]}]},{"id":"conditional-power-attachment","name":"Conditional power attachment","description":"Handles power requirements only where the attachment supports a specified power role.","findings":[{"id":"power-role-and-constraints","name":"Power role and constraints","description":"Record the applicable power role, conductor usage, and enabling requirements while leaving complete power-system behavior to neighboring models.","questions":[{"text":"Does this attachment have a documented PD or endpoint PSE role, or is it data-only?","id":"power-role-and-constraints-q01","kind":"definition"},{"text":"Which power specification and interface checks govern whether power may be enabled on the proposed connection?","id":"power-role-and-constraints-q02","kind":"action"}]}]}]},{"id":"compatibility-and-verification","name":"Compatibility and verification","description":"Turns interface requirements and observed evidence into bounded connection decisions.","layers":[{"id":"peer-and-medium-fit","name":"Peer and medium fit","description":"Compares the local MDI, transmission medium, and remote interface.","findings":[{"id":"connection-assessment","name":"Connection assessment","description":"Record compatible operating modes and unresolved attachment, mapping, or signal mismatches across the proposed connection.","questions":[{"text":"Which operating modes are jointly supported by the local interface, peer interface, and selected medium?","id":"connection-assessment-q01","kind":"boundary"},{"text":"Which identified mismatch requires a configuration change, a different medium, or a different interface?","id":"connection-assessment-q02","kind":"action"}]}]},{"id":"mdi-test-evidence","name":"MDI test evidence","description":"Associates conformance decisions with reproducible interface measurements.","findings":[{"id":"conformance-and-diagnostic-limits","name":"Conformance and diagnostic limits","description":"Record test coverage, measured failures, and the limits of conclusions drawn from link status or end-to-end symptoms.","questions":[{"text":"Which test reports identify the tested port, PHY mode, reference plane, conditions, and governing limits?","id":"conformance-and-diagnostic-limits-q01","kind":"provenance"},{"text":"What additional measurement would distinguish an MDI defect from a medium fault, peer fault, or internal PHY problem?","id":"conformance-and-diagnostic-limits-q02","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-standards-and-regulation","name":"Standards and regulation","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these standards and regulation hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-standards-and-regulation-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of medium dependent interface this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Identify and document MDI port types and cabling on networks it is authorized to manage.","Diagnose link problems such as crossover or pair mismatches and report them."],"mustNot":["Connect to or tap a network medium it is not authorized to access.","Change cabling or port settings on a live network without authorization.","Apply power over cabling to equipment not designed to receive it."],"requiresHuman":["Changing physical connections on networks that carry critical services."]},"ethics":{"considerations":["Physical network access can expose others' communications."],"affectedParties":["Network users","Network administrators","Organizations relying on the network"]},"owners":{"steward":"The owner or operator of the network equipment.","roles":[],"masterSystems":[]},"relations":[{"target":"Q6046311","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.medium-dependent-interface","Wikidata: Q1421871 (https://www.wikidata.org/wiki/Q1421871)"]},"properties":{"applicability":"not-applicable","items":["Governing PHY specification: Ethernet PHY designation, standard edition, applicable clauses, amendments, and corrigenda","Transmission medium class: Balanced copper, optical fiber, coaxial, or another explicitly specified medium","MDI reference plane: Specified physical boundary and associated measurement fixture or de-embedding convention","Mechanical attachment profile: Connector or attachment specification, mating geometry, keying, and applicable contact assignment","Signal-path assignment: Contacts, pairs, lanes, or fibers mapped to their PHY-specific roles","Supported operating modes: Declared PHY modes, nominal bit rates in bit/s, and supported duplex or topology options","Electrical interface measurements: Profile-dependent voltage in V, impedance in ohms, and return loss in dB over a stated frequency range; not applicable for optical-only measurements","Optical interface measurements: Profile-dependent wavelength in nm and optical power in dBm, with measurement conditions; not applicable for electrical-only interfaces","Crossover configuration: MDI, MDI-X, automatic selection, unknown, or not applicable, qualified by PHY type","Power attachment role: Data-only, PD, endpoint PSE, unknown, or not applicable, with the governing power specification","Interface verification status: Untested, partially tested, conformant for a stated profile, nonconformant, or indeterminate"]},"recognition":{"applicability":"optional","items":["A network port, such as an eight-pin modular socket or an optical connector, on an Ethernet device."]},"capabilities":{"applicability":"required","items":["Resolve a port description into a PHY-specific MDI profile and identify missing evidence.","Compare a proposed medium and peer interface against mechanical, signal, mapping, and operating-mode requirements.","Determine whether crossover or automatic crossover settings are relevant to a connection problem.","Select electrical or optical measurements at the correct MDI reference plane.","Check conditional power attachment requirements before recommending power enablement.","Recommend connection, reconfiguration, retesting, or replacement based on documented mismatches."]},"hazards":{"applicability":"required","items":["Wrong pair wiring causes link failure or degraded speed.","Incorrect power over Ethernet can damage connected equipment."]},"interfaces":{"applicability":"required","items":["IEEE 802.3, Standard for Ethernet, Institute of Electrical and Electronics Engineers."]},"context":{"applicability":"required","items":["A medium dependent interface is encountered where an Ethernet physical-layer device connects to its specified transmission medium.","It is used when assessing port, connector and cabling compatibility or diagnosing physical connection problems.","Its requirements depend on the particular Ethernet physical-layer type and medium."]}},"sources":[{"title":"Wikidata item Q1421871: medium dependent interface","url":"https://www.wikidata.org/wiki/Q1421871","note":"identity and sense of the item"},{"title":"Wikipedia: Medium-dependent interface","url":"https://en.wikipedia.org/wiki/Medium-dependent_interface","note":"general description of the item"}],"openQuestions":["Does the registry intend the general IEEE 802.3 interface concept or the narrower use of MDI contrasted with MDI-X on twisted-pair ports?","Which existing Vercy model, if any, already owns this interface concept and should remain its single source of truth?","Which PHY families and standard editions should receive detailed profiles, including applicable corrections to interface limits?","How should the INF / INF.KNW classification distinguish the abstract interface contract from physical port implementations?","Which power attachment variants and non-connector implementations must the initial model cover?"],"resources":{"spec":"/models/things/publications/thing-q1421871/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q1421871/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T11:13:21Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:26+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane INF: no invented physical properties."},"score":1.0}}