instruction:
Topic: 400G Transceiver Selection
Audience: network engineers and procurement teams

output:
{
  "situation": "Signing a PO for 400G this week, choosing between SR4 and DR4 without realizing the fiber plant doesn't support one of them",
  "core_decision": "SR4 vs DR4 — same connector, completely different fiber infrastructure requirement. Wrong choice means rewiring the datacenter.",
  "why_it_matters": "Budget is locked. Fiber plant is what it is. The choice you make today is the problem you debug in 3 months.",
  "rejected_angles": ["what is 400G ethernet", "history of high-speed transceivers", "why 400G is the future", "complete guide to selecting optics"],
  "title_hint": "Keep the title honest — if pricing isn't in the article, don't put it in the title"
}


instruction:
Topic: 800G deployment considerations
Audience: architects and procurement

output:
{
  "situation": "First 800G deployment in a spine that wasn't designed for it — the switch is there, the optics are there, but behavior under load is different than expected",
  "core_decision": "When 800G actually makes sense vs when you're just buying the newest thing because the vendor said so",
  "why_it_matters": "The ecosystem is still maturing. Specific problems that don't exist at 400G will show up at 800G.",
  "rejected_angles": ["800G speeds explained", "comparison of all 800G form factors", "is 800G right for you"],
  "title_hint": "Be specific — '800G in Production: What Nobody Told You' beats '800G: Everything You Need to Know'"
}


instruction:
Blog post topic: 800G QSFP-DD Market 2026 — Pricing Trends and Deployment Reality

Background data / market context:
- 800G QSFP-DD prices dropped from $2,400 avg in Q1 2024 to $890 avg in Q4 2025
- LightCounting projects 8.2M units shipped in 2026
- Major adopters: hyperscalers (AWS, Meta, Google) driving 70% of volume
- White-box/third-party share now 34% of 800G market (up from 8% in 2023)
- Key form factors: QSFP-DD800 (dominant), OSFP (Nvidia GPU clusters)

Key points to cover:
- Price trajectory and when ISPs can realistically justify 800G
- OSFP vs QSFP-DD split
- Third-party compatibility status on Arista 7800 and Cisco 8000 series

output:
## TL;DR
- 800G QSFP-DD prices have fallen 63% in 24 months — from $2,400 to $890 per module
- Hyperscalers consume 70% of 2026 volume; ISP deployment is 12-18 months behind
- Third-party compatibility on Arista 7800R3 is production-ready; Cisco 8000 requires IOS XR 7.9.1+

## The Price Collapse That's Reshaping 800G Timelines

800G QSFP-DD modules cost $2,400 apiece in Q1 2024. They cost $890 in Q4 2025. That 63% decline in 24 months is not a market anomaly — it is the same curve that 400G ran from 2020 to 2022, compressed by higher manufacturing volumes and aggressive white-box competition.

LightCounting projects 8.2 million 800G units shipped in 2026. For context: the entire 400G market shipped 6.1 million units in its first full year. 800G is scaling faster, and the pricing will follow.

The inflection point for ISPs — where 800G port cost per Gbps undercuts 2x400G — is approximately Q3 2026 at current decline rates. Procurement teams planning 3-year refresh cycles should be running lab evaluations now, not waiting for list prices to drop further.

## QSFP-DD vs OSFP: The Form Factor Split Is Real

The market is not converging on a single 800G form factor. QSFP-DD800 dominates carrier and enterprise deployments at roughly 68% of units. OSFP holds 31%, concentrated almost entirely in GPU cluster interconnects — primarily Nvidia InfiniBand and Spectrum-X deployments where the higher power ceiling (15W vs 10W for QSFP-DD) is necessary for 800G-DR8 optics over longer distances.

If you're deploying Arista 7800, Cisco 8000, or Juniper PTX10000, you are in QSFP-DD territory. If you're building GPU fabric with Nvidia Quantum-2 or Spectrum-4 switches, OSFP is your form factor.

The overlap is small. Do not let vendor marketing confuse this.

## Third-Party Compatibility: Where Things Actually Stand

Third-party 800G modules now hold 34% market share, up from 8% in 2023. The driving factor: lead times. OEM 800G QSFP-DD modules from Cisco and Juniper carried 16-24 week lead times through most of 2024. Third-party vendors like II-VI (now Coherent), InnoLight, and Hisense shipped in 4-6 weeks.

Compatibility status as of Q1 2026:

| Platform | Third-Party Status | Notes |
|---|---|---|
| Arista 7800R3 | Production-ready | EOS 4.30.0+ required |
| Cisco 8201-32FH | Compatible | IOS XR 7.9.1+, no `service unsupported-transceiver` warning |
| Cisco 8808 | Compatible | Same IOS XR requirement |
| Juniper PTX10016 | Compatible | Junos 23.2R1+, DOM works |
| Nokia 7750 SR-s | Partial | SR OS 22.10+ needed, some DOM limitations |

"Compatible" here means tested and shipping in production networks, not just lab-validated.

## Market Numbers

- Total 800G addressable market 2026: $7.3 billion (Dell'Oro Group estimate)
- Hyperscaler share of unit volume: ~70% (AWS, Meta, Google, Microsoft combined)
- ISP/carrier share: ~18%
- Enterprise: ~12%
- Average selling price trend: expect sub-$700 by Q4 2026 for standard 800G-DR1 QSFP-DD
- 800G-LR1 (10 km SMF): still at $1,200-1,800 range — coherent DSP cost not yet compressed

## Practical Implications

For network engineers: Start your 800G lab qualification now if you're on Arista 7800 or Cisco 8000. The IOS XR version requirement is the main gotcha — check your current version before ordering. Use DOM monitoring from day one; 800G optics run hotter and the thermal headroom is tighter than 400G.

For procurement: Build vendor diversity into your 800G BOM. Single-source on OEM at 800G creates lead time risk. Third-party from Coherent or InnoLight with a compatibility verification (TIP database has 2,400+ tested entries) is a defensible procurement strategy.

The 800G market is past the early-adopter phase. It is now a procurement and logistics problem, not a technology risk problem.


instruction: Explain SFF-8024 code QSFP28-SR4

input: Specification: 40 Gbps, 4x 10 Gbps lanes, 70m MMF, LC duplex

output:
**QSFP28-SR4**

40 Gbps, 4x 10 Gbps lanes, 70m MMF, LC duplex

**Context**: Standard datacenter interconnect, highest port density in 40G era


instruction: Explain SFF-8024 code QSFP28-100G-DR

input: Specification: 100 Gbps, single-lane coherent, 10km SMF, LC duplex

output:
**QSFP28-100G-DR**

100 Gbps, single-lane coherent, 10km SMF, LC duplex

**Context**: ISP backbone interconnects, common in 100G spine networks


instruction: Explain SFF-8024 code QSFP-DD800-SR8

input: Specification: 800 Gbps, 8x 100 Gbps, 70m MMF, MPO-16

output:
**QSFP-DD800-SR8**

800 Gbps, 8x 100 Gbps, 70m MMF, MPO-16

**Context**: Latest hyperscaler standard, rapidly replacing 2x400G deployments


instruction: Explain SFF-8024 code CFP2-ACO

input: Specification: 100 Gbps, analog coherent, tunable 191.35-196.10 THz

output:
**CFP2-ACO**

100 Gbps, analog coherent, tunable 191.35-196.10 THz

**Context**: Telecom long-haul, 80+ km reach, supports flexible grid (50 GHz/6.25 GHz spacing)


instruction: Analyze market trend: 400G QSFP-DD pricing trajectory

input:
Source: LightCounting Market Data
Data: Q1 2024: $890/unit | Q4 2024: $650/unit | Q1 2025: $520/unit

output:
## 400G QSFP-DD pricing trajectory

Q1 2024: $890/unit | Q4 2024: $650/unit | Q1 2025: $520/unit

**Analysis**: ISP addressable market inflection point: $400/unit by Q4 2025


instruction: Analyze market trend: 800G QSFP-DD market 2026

input:
Source: Dell'Oro Group analyst forecast
Data: Current: $890/unit | Projected Q3 2026: <$700/unit

output:
## 800G QSFP-DD market 2026

Current: $890/unit | Projected Q3 2026: <$700/unit

**Analysis**: Third-party vendor share growing 8% YoY; OEM prices staying premium


instruction: Translate technical term (English → German)

input: Single-Mode Fiber (SMF) requires coherent optics for 100G+ distances

output: Monomodales Quarz (SMF) erfordert kohärente Optik für 100G+ Distanzen


instruction: Translate technical term (German → English)

input: Monomodales Quarz (SMF) erfordert kohärente Optik für 100G+ Distanzen

output: Single-Mode Fiber (SMF) requires coherent optics for 100G+ distances


instruction: Translate technical term (English → German)

input: QSFP-DD form factor supports 400G and 800G with same connector footprint

output: Der QSFP-DD-Formfaktor unterstützt 400G und 800G mit demselben Stecker-Footprint


instruction: Translate technical term (German → English)

input: Der QSFP-DD-Formfaktor unterstützt 400G und 800G mit demselben Stecker-Footprint

output: QSFP-DD form factor supports 400G and 800G with same connector footprint


instruction: Translate technical term (English → German)

input: Multi-Mode Fiber (MMF) is limited to ~70m at 400G data rates

output: Mehrmodiges Quarz (MMF) ist auf ~70m bei 400G-Datenraten begrenzt


instruction: Translate technical term (German → English)

input: Mehrmodiges Quarz (MMF) ist auf ~70m bei 400G-Datenraten begrenzt

output: Multi-Mode Fiber (MMF) is limited to ~70m at 400G data rates