import type { TrainingLesson } from "./types";

export const testingBuyingLessons: TrainingLesson[] = [
  {
    id: "test-equipment",
    category: "testing-buying",
    title: "Fiber Optic Test Equipment",
    title_de: "Glasfaser-Testgeraete",
    level: "beginner",
    duration_min: 12,
    summary:
      "Every fiber installation requires testing. Learn the essential test tools — OTDR, optical power meter, VFL, and inspection microscope — what they measure and when to use each.",
    summary_de:
      "Jede Glasfaserinstallation erfordert Tests. Lernen Sie die wesentlichen Testgeraete — OTDR, optisches Leistungsmessgeraet, VFL und Inspektionsmikroskop — was sie messen und wann jedes eingesetzt wird.",
    tags: ["otdr", "power-meter", "vfl", "testing", "inspection", "tools"],
    sections: [
      {
        heading: "Essential Test Equipment Overview",
        heading_de: "Ueberblick ueber wesentliche Testgeraete",
        blocks: [
          {
            type: "table",
            headers: ["Tool", "What It Measures", "When to Use", "Approx. Price"],
            headers_de: ["Geraet", "Was es misst", "Wann einsetzen", "Ungefaehre Kosten"],
            rows: [
              ["Optical Power Meter (OPM)", "Received optical power in dBm", "Verify received power, acceptance testing", "$150–500"],
              ["Light Source", "Stable reference power output", "Paired with OPM for IL testing", "$100–400"],
              ["OPM + Source Kit", "Insertion Loss (IL)", "Full link acceptance testing", "$300–800"],
              ["OTDR", "Distance, loss per event, fiber trace", "Long fiber runs, splice/connector maps, breaks", "$2,000–25,000"],
              ["VFL (Visual Fault Locator)", "Visible red light in fiber", "Find bends, breaks, continuity check, ID fibers", "$50–200"],
              ["Fiber Inspection Microscope / Video Probe", "Connector endface contamination", "Before mating any connector", "$200–1,500"],
              ["Optical Spectrum Analyzer (OSA)", "All DWDM channel powers and wavelengths", "WDM system commissioning and troubleshooting", "$15,000–100,000"],
              ["BERT (Bit Error Rate Tester)", "End-to-end bit error rate", "Final acceptance, troubleshooting transient errors", "$5,000–50,000"],
            ],
          },
          {
            type: "callout",
            variant: "key",
            text: "For most enterprise and data center work, you need only three tools: (1) Fiber inspection video probe, (2) OPM + light source kit, and (3) VFL. These three tools solve 80%+ of all fiber problems and together cost under $1,500.",
            text_de:
              "Fuer die meisten Enterprise- und Rechenzentrumsarbeiten benoetigen Sie nur drei Geraete: (1) Glasfaser-Inspektions-Videosonde, (2) OPM + Lichtquellen-Kit und (3) VFL. Diese drei Geraete losen 80%+ aller Glasfaserprobleme und kosten zusammen unter 1.500 EUR.",
          },
        ],
      },
      {
        heading: "The OTDR (Optical Time-Domain Reflectometer)",
        heading_de: "Das OTDR (Optisches Zeitbereichs-Reflektometer)",
        blocks: [
          {
            type: "p",
            text: "An OTDR sends short pulses of light into the fiber and measures the returning backscattered light over time. Since the speed of light in fiber is known (~5 ns/m), the OTDR can calculate the exact distance to any reflection or scattering event — splices, connectors, bends, and breaks — and measure the loss at each point. The result is an OTDR trace: a graph of distance vs. backscatter level.",
            text_de:
              "Ein OTDR sendet kurze Lichtimpulse in die Faser und misst das zeitabhaengige zurueckkehrende Streulicht. Da die Lichtgeschwindigkeit in der Faser bekannt ist (~5 ns/m), kann das OTDR den genauen Abstand zu jedem Reflexions- oder Streuereignis — Spleisse, Stecker, Biegungen und Brueche — berechnen und den Verlust an jedem Punkt messen.",
          },
          {
            type: "ul",
            items: [
              "Reflective events (spikes up then down): connectors, air gaps, mechanical splices — appear as peaks",
              "Non-reflective events (step down): fusion splices, bends, macrobending — appear as steps",
              "End of fiber: large reflective peak or flat line into noise floor",
              "OTDR dead zone: first 5–50m near the OTDR is unmeasurable — use launch cable (25–50m) to push the dead zone past the first connector",
            ],
            items_de: [
              "Reflektive Ereignisse (Spitze nach oben dann unten): Stecker, Luftspuecken, Mechanische Spleisse — erscheinen als Peaks",
              "Nicht-reflektive Ereignisse (Schritt nach unten): Fusionsspleisse, Biegungen, Makrobiegungen — erscheinen als Stufen",
              "Faserende: grosse reflektive Spitze oder flache Linie zum Rauschboden",
              "OTDR-Totzone: erste 5–50 m nahe dem OTDR sind nicht messbar — Startkabel (25–50 m) verwenden, um die Totzone hinter den ersten Stecker zu verschieben",
            ],
          },
        ],
      },
      {
        heading: "Fiber Inspection — Why It Matters",
        heading_de: "Faserninspektion — Warum sie wichtig ist",
        blocks: [
          {
            type: "p",
            text: "A single dust particle on a connector endface can cause 1–40 dB of additional loss — enough to fail a link budget or cause intermittent errors. Fiber inspection with a 200×–400× video probe takes 30 seconds and catches this immediately. IEC 61300-3-35 defines the pass/fail criteria: Zone A (core) must be Grade A (no defects) for single-mode.",
            text_de:
              "Ein einziges Staubpartikel auf einem Steckerendgesicht kann 1–40 dB zusaetzlichen Verlust verursachen — genug, um ein Linkbudget scheitern zu lassen oder intermittierende Fehler zu verursachen. Die Faserinspektiion mit einer 200×–400×-Videosonde dauert 30 Sekunden und erkennt das sofort. IEC 61300-3-35 definiert die Pass/Fail-Kriterien: Zone A (Kern) muss fuer Einzelmodefaser Grad A (keine Defekte) sein.",
          },
          {
            type: "callout",
            variant: "warning",
            text: "NEVER look directly into a fiber connector with the naked eye or non-filtered scope — even 'dark' fibers may carry infrared laser light that can instantly and permanently damage your eyes. Always use a proper fiber inspection probe with IR filter.",
            text_de:
              "NIEMALS direkt in einen Faserstecker mit blossem Auge oder ungefilterten Messinstrumenten schauen — selbst 'dunkle' Fasern koennen Infrarot-Laserlicht fuehren, das Ihre Augen sofort und dauerhaft schaedigen kann. Immer eine ordentliche Faserinspetkionssonde mit IR-Filter verwenden.",
          },
        ],
      },
    ],
    quiz: [
      {
        id: "test-eq-q1",
        lesson: "test-equipment",
        q: "What is the primary function of an OTDR?",
        q_de: "Was ist die Hauptfunktion eines OTDR?",
        options: [
          "Measure the total bandwidth of a fiber link",
          "Send pulses and measure backscattered light to locate splices, connectors, and breaks with distance information",
          "Measure the optical power output of a transceiver module",
          "Test the bit error rate of a data link",
        ],
        options_de: [
          "Gesamtbandbreite einer Faserverbindung messen",
          "Impulse senden und Streulicht messen, um Spleisse, Stecker und Brueche mit Abstandsangabe zu lokalisieren",
          "Optische Ausgangsleistung eines Transceiver-Moduls messen",
          "Bitfehlerrate einer Datenverbindung testen",
        ],
        answer: 1,
        explanation:
          "An OTDR locates and measures the loss of events (splices, connectors, bends, breaks) in a fiber by analyzing the time and amplitude of backscattered light from pulses it sends into the fiber.",
        explanation_de:
          "Ein OTDR lokalisiert und misst den Verlust von Ereignissen (Spleisse, Stecker, Biegungen, Brueche) in einer Faser durch Analyse von Zeit und Amplitude des Streulichts aus Impulsen, die es in die Faser sendet.",
      },
      {
        id: "test-eq-q2",
        lesson: "test-equipment",
        q: "Why must you NEVER look directly into a fiber with your naked eye?",
        q_de: "Warum darf man NIEMALS direkt mit blossem Auge in eine Faser schauen?",
        options: [
          "You will contaminate the fiber end with your eye",
          "Invisible infrared laser light can instantly and permanently damage your eyes",
          "The fiber glow will hurt your eyes temporarily",
          "It is only a precaution for multimode fiber, not single-mode",
        ],
        options_de: [
          "Sie kontaminieren das Faserende mit Ihrem Auge",
          "Unsichtbares Infrarot-Laserlicht kann Ihre Augen sofort und dauerhaft schaedigen",
          "Das Faserleuchten verletzt voruebergehend Ihre Augen",
          "Es ist nur eine Vorsichtsmassnahme fuer Mehrmodefaser, nicht Einzelmodefaser",
        ],
        answer: 1,
        explanation:
          "Fiber optic systems use infrared lasers (850nm, 1310nm, 1550nm) invisible to the naked eye but capable of causing instant permanent eye damage. Always use a proper inspection scope with IR filter.",
        explanation_de:
          "Glasfasersysteme verwenden Infrarot-Laser (850 nm, 1310 nm, 1550 nm), die fuer das blosse Auge unsichtbar sind, aber sofortige dauerhafte Augenschaeden verursachen koennen. Immer eine ordentliche Inspektionssonde mit IR-Filter verwenden.",
      },
      {
        id: "test-eq-q3",
        lesson: "test-equipment",
        q: "What is the purpose of a 'launch cable' when using an OTDR?",
        q_de: "Was ist der Zweck eines 'Startkabels' bei der Verwendung eines OTDRs?",
        options: [
          "To launch the OTDR software on a laptop",
          "To push the OTDR dead zone past the first connector so it can be measured",
          "To amplify the OTDR signal for longer reach",
          "To protect the OTDR port from laser damage",
        ],
        options_de: [
          "Um die OTDR-Software auf einem Laptop zu starten",
          "Um die OTDR-Totzone hinter den ersten Stecker zu verschieben, sodass er gemessen werden kann",
          "Um das OTDR-Signal fuer groessere Reichweite zu verstaerken",
          "Um den OTDR-Port vor Laserschaeden zu schuetzen",
        ],
        answer: 1,
        explanation:
          "The OTDR dead zone (first 5–50m) is unmeasurable because the receiver is still recovering from the large pulse. A 25–50m launch cable 'pushes' the dead zone past the first connector of interest, allowing it to be measured.",
        explanation_de:
          "Die OTDR-Totzone (erste 5–50 m) ist unmessbar, weil der Empfaenger noch vom grossen Impuls erholt. Ein 25–50-m-Startkabel 'verschiebt' die Totzone hinter den ersten interessierenden Stecker und ermoeglicht seine Messung.",
      },
    ],
  },

  {
    id: "buy-oem-vs-compatible",
    category: "testing-buying",
    title: "OEM vs. Compatible Transceivers: Facts vs. Myths",
    title_de: "OEM vs. kompatible Transceiver: Fakten vs. Mythen",
    level: "beginner",
    duration_min: 15,
    summary:
      "Compatible transceivers are often misunderstood. This lesson separates myths from facts, explains the manufacturing reality, quality tiers, and how to evaluate a compatible module supplier.",
    summary_de:
      "Kompatible Transceiver werden oft falsch verstanden. Diese Lektion trennt Mythen von Fakten, erklaert die Fertigungsrealitaet, Qualitaetsstufen und wie ein kompatibler Modulanbieter bewertet wird.",
    tags: ["oem", "compatible", "third-party", "quality", "myths", "tco"],
    sections: [
      {
        heading: "Who Actually Manufactures OEM Modules?",
        heading_de: "Wer stellt OEM-Module tatsaechlich her?",
        blocks: [
          {
            type: "p",
            text: "Cisco, Juniper, Arista, and other network vendors do NOT manufacture their own transceivers. They outsource production to a small number of optical module manufacturers (ODMs) — the same companies that also supply third-party compatible modules. The physical module is identical; only the EEPROM vendor programming and price differ.",
            text_de:
              "Cisco, Juniper, Arista und andere Netzwerkhersteller STELLEN ihre eigenen Transceiver NICHT her. Sie vergeben die Produktion an eine kleine Anzahl optischer Modulhersteller (ODMs) — dieselben Unternehmen, die auch kompatible Drittanbieter-Module liefern. Das physische Modul ist identisch; nur die EEPROM-Herstellerprogrammierung und der Preis unterscheiden sich.",
          },
          {
            type: "table",
            headers: ["Major ODM", "OEM customers (examples)", "Also sells compatible?"],
            headers_de: ["Grosser ODM", "OEM-Kunden (Beispiele)", "Verkauft auch kompatibel?"],
            rows: [
              ["II-VI (Coherent)", "Cisco, Juniper, HP", "Yes — via many rebranders"],
              ["Lumentum", "Cisco, Arista, Nokia", "Yes — via channel"],
              ["InnoLight", "Arista, hyperscalers", "Yes — major compatible supplier"],
              ["Hisense Broadband", "Hyperscalers, enterprise", "Yes — major compatible ODM"],
              ["Source Photonics", "Cisco, Calix, ADTRAN", "Yes — OEM and compatible"],
              ["JDSU / Viavi", "Cisco, Juniper", "Yes — mainly OEM now"],
            ],
          },
          {
            type: "callout",
            variant: "key",
            text: "The module that says 'Cisco SFP-10G-LR' and a FLEXOPTIX-coded compatible SFP+ LR may come from the same production line at InnoLight or II-VI. The difference is the EEPROM programming and the price tag — not the optical or electrical components.",
            text_de:
              "Das Modul mit der Aufschrift 'Cisco SFP-10G-LR' und ein FLEXOPTIX-kodiertes kompatibles SFP+ LR koennen von derselben Produktionslinie bei InnoLight oder II-VI stammen. Der Unterschied liegt in der EEPROM-Programmierung und dem Preisschild — nicht in den optischen oder elektrischen Komponenten.",
          },
        ],
      },
      {
        heading: "Common Myths — Debunked",
        heading_de: "Haeufige Mythen — Widerlegt",
        blocks: [
          {
            type: "table",
            headers: ["Myth", "Fact"],
            headers_de: ["Mythos", "Fakt"],
            rows: [
              [
                "Compatible modules damage switches",
                "FALSE — MSA-compliant modules meet the same electrical interface specs. There is no electrical difference that could cause hardware damage.",
              ],
              [
                "Using a third-party module voids the switch warranty",
                "FALSE (in most jurisdictions) — In the EU and US, using a third-party component does not void a product warranty unless the vendor can prove the component caused the damage. The Magnuson-Moss Warranty Act (US) and EU Directive 1999/44/EC protect consumers.",
              ],
              [
                "Compatible modules have lower quality / higher failure rates",
                "FALSE for Tier 1 — Tier 1 compatible modules from major ODMs have the same MTBF (300,000+ hours) as OEM modules from the same factory. Tier 3 budget modules may have higher failure rates.",
              ],
              [
                "Only OEM modules show DOM diagnostics",
                "FALSE — Properly coded compatible modules with full EEPROM programming show DOM on Cisco IOS, Arista EOS, Juniper Junos, and most other platforms.",
              ],
              [
                "You can't get support if you use compatible modules",
                "PARTIALLY TRUE — Switch vendor TAC (e.g., Cisco) may decline to assist until you swap to an OEM module. But the module itself and your fiber supplier are responsible for module support.",
              ],
            ],
          },
        ],
      },
      {
        heading: "Quality Tiers",
        heading_de: "Qualitaetsstufen",
        blocks: [
          {
            type: "table",
            headers: ["Tier", "Description", "MTBF", "DOM Support", "Where to Buy"],
            headers_de: ["Stufe", "Beschreibung", "MTBF", "DOM-Unterstuetzung", "Wo kaufen"],
            rows: [
              ["Tier 1 (OEM)", "OEM-branded, same ODM", "300,000+ h", "Full", "Cisco, Juniper, Arista shops"],
              ["Tier 1 (Compatible)", "Major ODM, full EEPROM, ISO 9001, full DOM, coded per platform", "300,000+ h", "Full", "Specialist: FLEXOPTIX, fs.com, Finisar-compatible"],
              ["Tier 2 (Compatible)", "Rebrand of Tier 1 or Tier 2 ODM, may have limited DOM, partial coding", "200,000–300,000 h", "Partial", "Some online resellers"],
              ["Tier 3 (Budget)", "Unknown ODM, no testing data, may lack DOM, partial EEPROM", "<100,000 h", "Often missing", "Avoid for production networks"],
            ],
          },
          {
            type: "callout",
            variant: "tip",
            text: "How to verify a Tier 1 compatible supplier: (1) Ask for full EEPROM dump for your target platform, (2) Request MTBF data from the ODM datasheet, (3) Confirm DOM parameter coverage, (4) Check warranty terms (minimum 3 years recommended), (5) Ask if they use ISO 9001 certified ODMs.",
            text_de:
              "Wie ein Tier-1-Kompatibel-Anbieter verifiziert wird: (1) Vollstaendigen EEPROM-Dump fuer Zielplattform anfragen, (2) MTBF-Daten aus dem ODM-Datenblatt anfordern, (3) DOM-Parameter-Abdeckung bestaetigen, (4) Garantiebedingungen pruefen (mindestens 3 Jahre empfohlen), (5) Pruefen ob ISO-9001-zertifizierte ODMs verwendet werden.",
          },
        ],
      },
    ],
    quiz: [
      {
        id: "buy-oem-q1",
        lesson: "buy-oem-vs-compatible",
        q: "Who manufactures Cisco SFP+ modules?",
        q_de: "Wer stellt Cisco SFP+-Module her?",
        options: [
          "Cisco manufactures all their own modules in-house",
          "ODMs like II-VI, Lumentum, InnoLight — same companies that also make compatible modules",
          "Only US-based manufacturers approved by Cisco",
          "Joint venture between Cisco and Huawei",
        ],
        options_de: [
          "Cisco stellt alle eigenen Module intern her",
          "ODMs wie II-VI, Lumentum, InnoLight — dieselben Unternehmen, die auch kompatible Module herstellen",
          "Nur US-basierte von Cisco genehmigte Hersteller",
          "Joint Venture zwischen Cisco und Huawei",
        ],
        answer: 1,
        explanation:
          "Cisco outsources transceiver manufacturing to major ODMs (Original Design Manufacturers) like II-VI (Coherent), Lumentum, and InnoLight — the same companies that manufacture compatible modules for other brands.",
        explanation_de:
          "Cisco vergibt die Transceiver-Fertigung an grosse ODMs (Original Design Manufacturers) wie II-VI (Coherent), Lumentum und InnoLight — dieselben Unternehmen, die kompatible Module fuer andere Marken herstellen.",
      },
      {
        id: "buy-oem-q2",
        lesson: "buy-oem-vs-compatible",
        q: "A Tier 1 compatible module from a major ODM has what MTBF compared to OEM?",
        q_de: "Ein Tier-1-kompatibles Modul von einem grossen ODM hat welche MTBF im Vergleich zu OEM?",
        options: [
          "Much lower — typically 50,000 hours",
          "Slightly lower — typically 200,000 hours vs 300,000 OEM",
          "Equivalent — typically 300,000+ hours from the same factory",
          "Higher — because compatible modules are newer",
        ],
        options_de: [
          "Viel niedriger — typisch 50.000 Stunden",
          "Etwas niedriger — typisch 200.000 Stunden vs 300.000 OEM",
          "Gleichwertig — typisch 300.000+ Stunden aus derselben Fabrik",
          "Hoeher — weil kompatible Module neuer sind",
        ],
        answer: 2,
        explanation:
          "Tier 1 compatible modules from major ODMs (the same factories making OEM modules) have equivalent MTBF — typically 300,000+ hours. The failure rate difference between OEM and Tier 1 compatible is negligible.",
        explanation_de:
          "Tier-1-kompatible Module von grossen ODMs (denselben Fabriken, die OEM-Module herstellen) haben gleichwertige MTBF — typisch 300.000+ Stunden. Der Ausfallratenunterschied zwischen OEM und Tier-1-kompatibel ist vernachlaessigbar.",
      },
      {
        id: "buy-oem-q3",
        lesson: "buy-oem-vs-compatible",
        q: "Cisco TAC asks you to swap a third-party module. What should you do?",
        q_de: "Cisco TAC bittet Sie, ein Drittanbieter-Modul auszutauschen. Was sollten Sie tun?",
        options: [
          "Always swap immediately — TAC knows best",
          "Refuse — Cisco has no right to make this request",
          "Understand this is a support policy: swap for diagnosis if needed, but the module may not be the cause",
          "Escalate to Cisco management",
        ],
        options_de: [
          "Sofort tauschen — TAC weiss es am besten",
          "Ablehnen — Cisco hat kein Recht, das zu verlangen",
          "Verstehen, dass dies eine Support-Richtlinie ist: zum Diagnostizieren tauschen wenn noetig, aber das Modul ist moeglicherweise nicht die Ursache",
          "An das Cisco-Management eskalieren",
        ],
        answer: 2,
        explanation:
          "Cisco TAC's policy is to not support third-party modules. If TAC asks you to swap, understand this is a support policy — not evidence the module is faulty. Swap for diagnostic purposes if needed, but the compatible module itself is likely not the root cause.",
        explanation_de:
          "Die Cisco-TAC-Richtlinie ist es, keine Drittanbieter-Module zu unterstuetzen. Wenn TAC Sie bittet zu tauschen, verstehen Sie, dass dies eine Support-Richtlinie ist — kein Beweis, dass das Modul fehlerhaft ist. Zum Diagnostizieren tauschen wenn noetig, aber das kompatible Modul selbst ist wahrscheinlich nicht die Grundursache.",
      },
      {
        id: "buy-oem-q4",
        lesson: "buy-oem-vs-compatible",
        q: "What is the most important indicator of a Tier 1 compatible module supplier?",
        q_de: "Was ist der wichtigste Indikator fuer einen Tier-1-Kompatibel-Modulanbieter?",
        options: [
          "They have the lowest price",
          "They can provide MTBF data, full EEPROM dump, ISO 9001 ODM certification, and DOM support",
          "They are based in Europe",
          "They have the most product listings",
        ],
        options_de: [
          "Sie haben den niedrigsten Preis",
          "Sie koennen MTBF-Daten, vollstaendigen EEPROM-Dump, ISO-9001-ODM-Zertifizierung und DOM-Unterstuetzung bereitstellen",
          "Sie sind in Europa ansaessig",
          "Sie haben die meisten Produktlistungen",
        ],
        answer: 1,
        explanation:
          "A Tier 1 compatible supplier can provide: MTBF data from ODM datasheets, full EEPROM programming samples, ISO 9001 ODM certification, full DOM support for your target platform, and a 3-year warranty.",
        explanation_de:
          "Ein Tier-1-Kompatibel-Anbieter kann bereitstellen: MTBF-Daten aus ODM-Datenblaettern, vollstaendige EEPROM-Programmerproben, ISO-9001-ODM-Zertifizierung, vollstaendige DOM-Unterstuetzung fuer die Zielplattform und 3 Jahre Garantie.",
      },
    ],
  },

  {
    id: "buy-datasheet",
    category: "testing-buying",
    title: "How to Read a Transceiver Datasheet",
    title_de: "Wie man ein Transceiver-Datenblatt liest",
    level: "beginner",
    duration_min: 12,
    summary:
      "A transceiver datasheet contains everything you need to know about module performance. Learn which parameters are critical, what typical values look like, and which red flags indicate a low-quality module.",
    summary_de:
      "Ein Transceiver-Datenblatt enthaelt alles, was Sie ueber die Modulleistung wissen muessen. Lernen Sie, welche Parameter kritisch sind, wie typische Werte aussehen und welche roten Flaggen auf ein minderwertiges Modul hinweisen.",
    tags: ["datasheet", "specifications", "tx-power", "rx-sensitivity", "buying"],
    sections: [
      {
        heading: "Key Transmitter Parameters",
        heading_de: "Wichtige Sender-Parameter",
        blocks: [
          {
            type: "table",
            headers: ["Parameter", "Typical Value (10G LR)", "What It Means"],
            headers_de: ["Parameter", "Typischer Wert (10G LR)", "Bedeutung"],
            rows: [
              ["Center wavelength", "1310 nm ± 50nm", "Optical wavelength — must match system filters if WDM"],
              ["TX output power (min)", "-8.2 dBm", "Worst-case minimum power out — use this for link budget"],
              ["TX output power (max)", "+0.5 dBm", "Maximum power — if short links, check for overpower"],
              ["Extinction ratio (min)", "8.2 dB", "Ratio of '1' to '0' power — lower = worse signal quality"],
              ["Side mode suppression ratio (SMSR)", ">30 dB", "Single-mode laser purity — low SMSR causes interference"],
            ],
          },
          {
            type: "callout",
            variant: "warning",
            text: "Always use the MINIMUM TX power for link budget calculations — never the typical or maximum value. The minimum guaranteed value is what the module will deliver under worst-case temperature and aging conditions.",
            text_de:
              "Fuer Linkbudget-Berechnungen immer den MINDEST-TX-Leistungswert verwenden — niemals den typischen oder maximalen Wert. Der garantierte Mindestwert ist das, was das Modul unter Worst-Case-Temperatur und Alterungsbedingungen liefern wird.",
          },
        ],
      },
      {
        heading: "Key Receiver Parameters",
        heading_de: "Wichtige Empfaenger-Parameter",
        blocks: [
          {
            type: "table",
            headers: ["Parameter", "Typical Value (10G LR)", "What It Means"],
            headers_de: ["Parameter", "Typischer Wert (10G LR)", "Bedeutung"],
            rows: [
              ["RX sensitivity (max)", "-14.4 dBm", "Minimum received power for BER 10⁻¹² — link budget input"],
              ["RX maximum input power", "+0.5 dBm", "Maximum power before saturation — check for overpower on short links"],
              ["Return loss (min)", "26 dB", "Reflected power — lower return loss causes laser instability"],
              ["BER at sensitivity", "10⁻¹²", "One bit error in 1 trillion bits transmitted — the standard target"],
            ],
          },
        ],
      },
      {
        heading: "Environmental and General Parameters",
        heading_de: "Umgebungs- und allgemeine Parameter",
        blocks: [
          {
            type: "table",
            headers: ["Parameter", "Commercial", "Industrial", "Extended"],
            headers_de: ["Parameter", "Kommerziell", "Industrie", "Erweitert"],
            rows: [
              ["Operating temperature", "0 to +70°C", "-40 to +85°C", "-40 to +85°C or wider"],
              ["Storage temperature", "-40 to +85°C", "-40 to +85°C", "-40 to +85°C"],
              ["Humidity", "5–85% non-cond.", "5–95% non-cond.", "Full range"],
              ["Typical use case", "Indoor data center", "Outdoor / harsh env.", "Telco, military, aviation"],
            ],
          },
          {
            type: "callout",
            variant: "tip",
            text: "For outdoor equipment enclosures or industrial environments (factories, warehouses), always specify Industrial temperature range (-40 to +85°C). Commercial modules may fail or degrade at temperatures above 70°C.",
            text_de:
              "Fuer Aussengehaeuseausruestung oder Industrieumgebungen (Fabriken, Lager) immer den Industrietemperaturbereich (-40 bis +85°C) angeben. Kommerzielle Module koennen bei Temperaturen ueber 70°C versagen oder sich verschlechtern.",
          },
        ],
      },
      {
        heading: "Red Flags in Datasheets",
        heading_de: "Rote Flaggen in Datenblaettern",
        blocks: [
          {
            type: "ul",
            items: [
              "No extinction ratio specification — means '0' level not controlled, higher BER likely",
              "Missing or unrealistically good RX sensitivity — 'typical only' without minimum = no guarantee",
              "No MTBF data or MTBF below 200,000 hours for standard modules",
              "No certifications listed (CE, FCC, RoHS) — compliance unknown",
              "No DOM register table — DOM may be missing or incorrect",
              "Only 'typical' values listed, no min/max — can't do reliable link budget",
              "No revision history or document date — likely not maintained / outdated spec",
            ],
            items_de: [
              "Kein Ausloeschungsverhaeltnis spezifiziert — bedeutet '0'-Pegel unkontrolliert, hohere BER wahrscheinlich",
              "Fehlende oder unrealistisch gute RX-Empfindlichkeit — 'nur typisch' ohne Mindestwert = keine Garantie",
              "Keine MTBF-Daten oder MTBF unter 200.000 Stunden fuer Standardmodule",
              "Keine Zertifizierungen angegeben (CE, FCC, RoHS) — Konformitaet unbekannt",
              "Keine DOM-Registertabelle — DOM koennte fehlen oder falsch sein",
              "Nur 'typische' Werte angegeben, kein Min/Max — zuverlaessiges Linkbudget nicht moeglich",
              "Keine Revisionshistorie oder Dokumentdatum — wahrscheinlich nicht gepflegt / veraltet",
            ],
          },
        ],
      },
    ],
    quiz: [
      {
        id: "buy-ds-q1",
        lesson: "buy-datasheet",
        q: "Which TX power value should you use for link budget calculation?",
        q_de: "Welchen TX-Leistungswert sollen Sie fuer die Linkbudget-Berechnung verwenden?",
        options: [
          "Maximum TX power — best case scenario",
          "Typical TX power — most representative value",
          "Minimum TX power — guaranteed worst case",
          "Average of minimum and maximum",
        ],
        options_de: [
          "Maximale TX-Leistung — Best-Case-Szenario",
          "Typische TX-Leistung — repraesentativster Wert",
          "Minimale TX-Leistung — garantierter Worst-Case",
          "Durchschnitt aus Minimum und Maximum",
        ],
        answer: 2,
        explanation:
          "Always use the MINIMUM guaranteed TX power for link budget. This ensures the link works under worst-case conditions: end-of-life, maximum temperature, lowest manufacturing tolerance.",
        explanation_de:
          "Fuer das Linkbudget immer die MINDEST-garantierte TX-Leistung verwenden. Das stellt sicher, dass die Verbindung unter Worst-Case-Bedingungen funktioniert: Lebensende, maximale Temperatur, niedrigste Fertigungstoleranz.",
      },
      {
        id: "buy-ds-q2",
        lesson: "buy-datasheet",
        q: "A datasheet shows RX sensitivity as '-14.4 dBm (typical)' with no minimum value. What is the concern?",
        q_de: "Ein Datenblatt zeigt RX-Empfindlichkeit als '-14.4 dBm (typisch)' ohne Mindestwert. Was ist das Problem?",
        options: [
          "No concern — typical values are sufficient for planning",
          "The sensitivity may be worse in some units — link budget is unreliable without a guaranteed minimum",
          "The module is using PAM4 instead of NRZ",
          "The module cannot be used in data centers",
        ],
        options_de: [
          "Kein Problem — typische Werte sind fuer die Planung ausreichend",
          "Die Empfindlichkeit kann bei einigen Einheiten schlechter sein — Linkbudget ohne garantierten Mindestwert unzuverlaessig",
          "Das Modul verwendet PAM4 statt NRZ",
          "Das Modul kann nicht in Rechenzentren verwendet werden",
        ],
        answer: 1,
        explanation:
          "A 'typical only' sensitivity value means there is no manufacturer guarantee. Some units may be significantly worse, making link budget calculations unreliable. Always require minimum (worst-case) values.",
        explanation_de:
          "Ein 'nur typischer' Empfindlichkeitswert bedeutet, dass es keine Herstellergarantie gibt. Einige Einheiten koennten deutlich schlechter sein, was Linkbudget-Berechnungen unzuverlaessig macht. Immer Mindestwerte (Worst-Case) fordern.",
      },
      {
        id: "buy-ds-q3",
        lesson: "buy-datasheet",
        q: "What temperature range is required for modules installed in outdoor equipment enclosures?",
        q_de: "Welcher Temperaturbereich ist fuer Module erforderlich, die in Aussengehaeuseausruestung installiert werden?",
        options: [
          "Commercial (0 to +70°C)",
          "Industrial (-40 to +85°C)",
          "Standard (−10 to +60°C)",
          "Extended (0 to +85°C)",
        ],
        options_de: [
          "Kommerziell (0 bis +70°C)",
          "Industrie (-40 bis +85°C)",
          "Standard (-10 bis +60°C)",
          "Erweitert (0 bis +85°C)",
        ],
        answer: 1,
        explanation:
          "Industrial temperature range (-40 to +85°C) is required for outdoor equipment or harsh environments. Commercial modules (0 to +70°C) may fail or degrade significantly in summer heat inside an outdoor enclosure.",
        explanation_de:
          "Der Industrietemperaturbereich (-40 bis +85°C) ist fuer Aussengeraete oder harte Umgebungen erforderlich. Kommerzielle Module (0 bis +70°C) koennen bei Sommerhitze in einem Aussengehaeuese versagen oder sich deutlich verschlechtern.",
      },
    ],
  },

  {
    id: "buy-tco",
    category: "testing-buying",
    title: "Total Cost of Ownership: OEM vs. Compatible",
    title_de: "Gesamtbetriebskosten: OEM vs. kompatibel",
    level: "intermediate",
    duration_min: 12,
    summary:
      "The real cost of transceivers goes beyond the purchase price. Learn to calculate Total Cost of Ownership (TCO) including power, spares, and support — and why compatible modules often save 60–80% over a 5-year horizon.",
    summary_de:
              "Die tatsaechlichen Kosten von Transceivern gehen ueber den Kaufpreis hinaus. Lernen Sie, die Gesamtbetriebskosten (TCO) einschliesslich Energie, Ersatzteile und Support zu berechnen — und warum kompatible Module ueber einen 5-Jahres-Horizont oft 60–80 % einsparen.",
    tags: ["tco", "cost", "oem", "compatible", "roi", "procurement"],
    sections: [
      {
        heading: "TCO Components",
        heading_de: "TCO-Komponenten",
        blocks: [
          {
            type: "ul",
            items: [
              "Purchase price: the obvious cost — OEM is typically 3–10× more expensive than Tier 1 compatible",
              "Power cost: P(W) × hours/year × $/kWh — usually small per port but significant at scale",
              "Spares cost: maintain 2–5% spare pool; compatible spares cost less",
              "Failure replacement labor: same regardless of module brand",
              "Support cost: OEM modules may be required for vendor TAC — factor in if support contracts are critical",
              "Lifecycle cost: transceivers don't need firmware updates — replace on failure only",
            ],
            items_de: [
              "Kaufpreis: die offensichtlichen Kosten — OEM ist typisch 3–10× teurer als Tier-1-kompatibel",
              "Energiekosten: P(W) × Stunden/Jahr × EUR/kWh — pro Port meist gering, bei Skalierung erheblich",
              "Ersatzteilkosten: 2–5% Ersatzteilpool pflegen; kompatible Ersatzteile kosten weniger",
              "Arbeitskosten fuer Fehlerersatz: gleich unabhaengig von der Modulmarke",
              "Support-Kosten: OEM-Module koennen fuer Hersteller-TAC erforderlich sein — beruecksichtigen wenn Support-Vertraege kritisch",
              "Lifecycle-Kosten: Transceiver benoetigen keine Firmware-Updates — nur bei Ausfall ersetzen",
            ],
          },
        ],
      },
      {
        heading: "5-Year TCO Example: 1000-Port Data Center",
        heading_de: "5-Jahres-TCO-Beispiel: 1000-Port-Rechenzentrum",
        blocks: [
          {
            type: "table",
            headers: ["Cost Item", "OEM (10G LR SFP+)", "Tier 1 Compatible (10G LR SFP+)", "Saving"],
            headers_de: ["Kostenpunkt", "OEM (10G LR SFP+)", "Tier 1 kompatibel (10G LR SFP+)", "Ersparnis"],
            rows: [
              ["Unit purchase price", "$800", "$80", "$720/port"],
              ["1,000 ports total (initial)", "$800,000", "$80,000", "$720,000"],
              ["5% spares (50 units)", "$40,000", "$4,000", "$36,000"],
              ["Power (1.5W × 1000 × 5yr)", "~$4,380", "~$4,380", "$0 (identical)"],
              ["Failure replacement (1% annual)", "$40,000", "$4,000", "$36,000"],
              ["Total 5-year TCO", "$884,380", "$92,380", "$792,000 (89% savings)"],
            ],
          },
          {
            type: "callout",
            variant: "key",
            text: "At 1000 ports of 10G LR, the 5-year saving from Tier 1 compatible vs. OEM is approximately $792,000. Even accounting for validation lab costs ($10–50K for thorough testing), the ROI is compelling.",
            text_de:
              "Bei 1.000 Ports mit 10G LR betraegt die 5-Jahres-Ersparnis durch Tier-1-kompatibel vs. OEM ungefaehr 792.000 USD. Selbst unter Beruecksichtigung der Validierungslaborkosten (10.000–50.000 USD fuer gruendliche Tests) ist der ROI ueberzeugend.",
          },
        ],
      },
      {
        heading: "Power Cost at Scale",
        heading_de: "Energiekosten in grossem Massstab",
        blocks: [
          {
            type: "formula",
            text: "Annual power cost = P_watts × 8760 h × ($/kWh) / 1000",
            desc: "Example: 100 SFP28 25G SR ports at 1.5W each = 150W × 8760h × $0.10/kWh = $131/year. At 1000 ports = $1,310/year — small but non-zero.",
            desc_de:
              "Beispiel: 100 SFP28 25G SR Ports mit je 1,5W = 150W × 8760h × 0,10 EUR/kWh = 131 EUR/Jahr. Bei 1.000 Ports = 1.310 EUR/Jahr — gering aber nicht null.",
          },
          {
            type: "p",
            text: "For high-power modules like 400G-ZR coherent (~15W per port), power cost becomes significant: 64 ports × 15W = 960W × 8760h × $0.10/kWh = $841/year. OEM vs. compatible modules at the same spec consume identical power — power cost does not differ.",
            text_de:
              "Fuer leistungsstarke Module wie 400G-ZR Coherent (~15W pro Port) werden Energiekosten erheblich: 64 Ports × 15W = 960W × 8760h × 0,10 EUR/kWh = 841 EUR/Jahr. OEM vs. kompatible Module mit gleicher Spezifikation verbrauchen identische Leistung — Energiekosten unterscheiden sich nicht.",
          },
        ],
      },
      {
        heading: "Spares Strategy",
        heading_de: "Ersatzteilstrategie",
        blocks: [
          {
            type: "ul",
            items: [
              "Maintain a 2–5% spare pool per transceiver type in production",
              "For critical links (data center spine, internet peering), keep ≥2 spares minimum",
              "Store spares in ESD-safe bags at 15–25°C, away from static and humidity",
              "Transceivers have no firmware to update — replaced units are plug-and-play (after EEPROM coding matches)",
              "Review spare pool annually against installed base changes",
            ],
            items_de: [
              "2–5% Ersatzteilpool pro Transceiver-Typ in der Produktion pflegen",
              "Fuer kritische Verbindungen (Rechenzentrum-Spine, Internet-Peering) mindestens ≥2 Ersatzteile bereithalten",
              "Ersatzteile in ESD-sicheren Beuteln bei 15–25°C, entfernt von Statik und Feuchtigkeit lagern",
              "Transceiver haben keine Firmware zum Aktualisieren — ersetzte Einheiten sind Plug-and-Play (nach korrekter EEPROM-Kodierung)",
              "Ersatzteilpool jaehrlich gegen Aenderungen des Bestands ueberpruefen",
            ],
          },
        ],
      },
    ],
    quiz: [
      {
        id: "buy-tco-q1",
        lesson: "buy-tco",
        q: "For 1000 ports of 10G LR, how much can a company save over 5 years by using Tier 1 compatible vs. OEM?",
        q_de: "Bei 1.000 Ports mit 10G LR wie viel kann ein Unternehmen ueber 5 Jahre durch die Verwendung von Tier-1-kompatibel vs. OEM einsparen?",
        options: [
          "About $10,000 — not significant",
          "About $100,000",
          "About $700,000–$800,000",
          "Nothing — compatible modules have higher maintenance costs that offset purchase savings",
        ],
        options_de: [
          "Etwa 10.000 USD — nicht bedeutsam",
          "Etwa 100.000 USD",
          "Etwa 700.000–800.000 USD",
          "Nichts — kompatible Module haben hoehere Wartungskosten, die Kaufersparnisse aufwiegen",
        ],
        answer: 2,
        explanation:
          "With OEM 10G LR at $800/port and compatible at $80/port, the initial saving alone is $720,000 at 1000 ports. Add spares and replacements over 5 years = ~$792,000 total saving.",
        explanation_de:
          "Mit OEM 10G LR zu 800 USD/Port und kompatibel zu 80 USD/Port betraegt die anfaengliche Ersparnis allein 720.000 USD bei 1.000 Ports. Dazu Ersatzteile und Austausch ueber 5 Jahre = ~792.000 USD Gesamtersparnis.",
      },
      {
        id: "buy-tco-q2",
        lesson: "buy-tco",
        q: "What spare pool percentage is recommended for production transceivers?",
        q_de: "Welcher Ersatzteilpool-Prozentsatz wird fuer Produktionstransceiver empfohlen?",
        options: ["0% — replace on failure only", "2–5%", "10–15%", "50% — one spare per port"],
        options_de: ["0% — nur bei Ausfall ersetzen", "2–5%", "10–15%", "50% — ein Ersatzgeraet pro Port"],
        answer: 1,
        explanation:
          "A 2–5% spare pool covers typical annual failure rates (0.5–1%) while minimizing tied-up capital. For critical links, maintain at least 2 individual spares regardless of percentage.",
        explanation_de:
          "Ein 2–5%-Ersatzteilpool deckt typische jaehrliche Ausfallraten (0,5–1%) ab und minimiert gebundenes Kapital. Fuer kritische Verbindungen mindestens 2 individuelle Ersatzteile unabhaengig vom Prozentsatz bereithalten.",
      },
      {
        id: "buy-tco-q3",
        lesson: "buy-tco",
        q: "Do OEM and Tier 1 compatible modules of the same spec consume different amounts of power?",
        q_de: "Verbrauchen OEM und Tier-1-kompatible Module derselben Spezifikation unterschiedlich viel Strom?",
        options: [
          "Yes — OEM modules are more power-efficient",
          "Yes — compatible modules consume more power",
          "No — modules of the same spec from the same ODM consume identical power",
          "It depends on the switch vendor",
        ],
        options_de: [
          "Ja — OEM-Module sind energieeffizienter",
          "Ja — kompatible Module verbrauchen mehr Strom",
          "Nein — Module gleicher Spezifikation vom gleichen ODM verbrauchen identisch viel Strom",
          "Es haengt vom Switch-Hersteller ab",
        ],
        answer: 2,
        explanation:
          "OEM and compatible modules of the same specification from the same ODM are electrically and optically identical — they consume the same power. Power cost does not differ between OEM and Tier 1 compatible.",
        explanation_de:
          "OEM und kompatible Module gleicher Spezifikation vom gleichen ODM sind elektrisch und optisch identisch — sie verbrauchen denselben Strom. Energiekosten unterscheiden sich nicht zwischen OEM und Tier-1-kompatibel.",
      },
    ],
  },
];
