ex9922025q3earningsprese

© Ciena Corporation 2025. All rights reserved. Proprietary Information.2 Forward-looking statements and non-GAAP measures You are encouraged to review the Investors section of our website, where we routinely post press releases, Securities and Exchange Commission (SEC) filings, recent news, financial results, supplemental financial information, and other announcements. From time to time, we exclusively post material information to this website along with other disclosure channels that we use. Information in this presentation and related comments of presenters contains certain forward-looking statements that involve risks and uncertainties. These statements are based on current expectations, forecasts, assumptions and other information available to the Company as of the date hereof. Forward- looking statements include statements regarding Ciena's expectations, beliefs, intentions or strategies regarding the future and can be identified by forward-looking words such as "anticipate," "believe," "could," "estimate," "expect," "intend," "may," "should," "will," and "would" or similar words. Ciena's actual results, performance or events may differ materially from these forward-looking statements made or implied due to a number of risks and uncertainties relating to Ciena's business, including: the effect of broader economic and market conditions on our customers, their spending and their businesses and markets; our ability to execute our business and growth strategies; the impact of macroeconomic conditions; the impact of the introduction of new technologies by us or our competitors; seasonality and the timing and size of customer orders, their delivery dates and our ability to recognize revenue relating to such sales; the level of competitive pressure we encounter; the product, customer and geographic mix of sales within the period; changes in foreign currency exchange rates; factors beyond our control such as natural disasters, climate change, acts of war or terrorism, geopolitical tensions or events, including but not limited to the ongoing conflicts between Ukraine and Russia, and Israel and groups based in the surrounding region, and public health emergencies, epidemics, or pandemics; changes in tax or trade regulations, including the imposition of tariffs, duties or efforts to withdraw from or materially modify international trade agreements; cyberattacks, data breaches or other security incidents involving our enterprise network environment or our products; regulatory changes, litigation involving our intellectual property or government investigations; and the other risk factors disclosed in Ciena’s periodic reports filed with the Securities and Exchange Commission (SEC) including its Annual Report on Form 10-K filed with the SEC on December 20, 2024 and included in its Quarterly Report on Form 10-Q for the third quarter of fiscal 2025 to be filed with the SEC. All information, statements, and projections in this presentation and the related earnings call speak only as of the date of this presentation and related earnings call. Ciena assumes no obligation to update any forward-looking or other information included in this presentation or related earnings calls, whether as a result of new information, future events or otherwise. In addition, this presentation includes historical, and may include prospective, non-GAAP measures of Ciena’s gross margin, operating expense, operating margin, EBITDA, and net income per share. These measures are not intended to be a substitute for financial information presented in accordance with GAAP. A reconciliation of non-GAAP measures used in this presentation to Ciena’s GAAP results for the relevant period can be found in the Appendix to this presentation. Additional information can also be found in our press release filed this morning and in our reports on Form 10-Q and Form 10-K filed with the Securities and Exchange Commission. With respect to Ciena’s expectations under “Business Outlook", Ciena is not able to provide a quantitative reconciliation of the adjusted (non-GAAP) gross margin, operating expense, operating margin and earnings per share guidance measures to the corresponding gross profit and gross profit percentage, and operating expense GAAP measures without unreasonable efforts. Ciena cannot provide meaningful estimates of the non-recurring charges and credits excluded from these non-GAAP measures due to the forward- looking nature of these estimates and their inherent variability and uncertainty. For the same reasons, Ciena is unable to address the probable significance of the unavailable information.

© Ciena Corporation 2025. All rights reserved. Proprietary Information.3 Table of Contents 1. Overview and Ciena's portfolio 2. Industry context and addressable market expansion 3. Ciena is positioned for accelerated growth 4. Fiscal Q3 2025 financial performance 5. Fiscal Q4 2025 outlook 6. Appendix

© Ciena Corporation 2025. All rights reserved. Proprietary Information.5 Ciena is the global leader in high-speed connectivity We build adaptive networks to support exponential growth in bandwidth demand – empowering our customers, partners, and communities to thrive in the AI era. With unparalleled expertise and innovation, our networking systems, components, automation software, and services revolutionize data transmission and network management. Note: Statistics as of Fiscal Year End 2024

© Ciena Corporation 2025. All rights reserved. Proprietary Information.11 An industry leader #1 Globally • Data center interconnect • Optical for cloud providers • Purpose-built/compact modular DCI #1 N. America • Optical for cloud providers • Total optical networking • Optical packet #2 Globally • Total optical networking • Optical Packet Optical Transport Report, 2Q25 #1 Globally • Purpose-built/compact modular DCI • SLTE WDM #1 N. America • Total optical networking • Purpose-built/compact modular DCI #2 Globally • Total optical networking Optical Networking Report, 1Q25 #1 Globally • Purpose-built/compact modular DCI • Optical for cloud and colo • SLTE WDM #1 N. America • Total optical networking • Optical for cloud and colo • Routing/Access #2 Globally • Total optical networking Transport Hardware & Markets Preliminary Report, 2Q25

© Ciena Corporation 2025. All rights reserved. Proprietary Information.13 Our future growth opportunities Long-term growth in core business plus new addressable markets provide an opportunity to outpace our traditional revenue CAGR over time

© Ciena Corporation 2025. All rights reserved. Proprietary Information.17 Q3 FY 2025 key highlights ▪ Non-telco represented 53% of total revenue ▪ Direct Cloud Provider revenue grew 94% YoY and represented 40% of total revenue ▪ EMEA revenue grew 38% YoY ▪ APAC revenue grew 24% YoY • First revenue quarter for WaveLogic 6 Nano coherent pluggable transceivers, both C-Band and L-Band variants • WL6e deployments continue to ramp driven by AI network buildouts with 11 new customers in the quarter, including a neoscaler in the top three • Record quarter for WaveLogic 5 Nano 400ZR shipments • WaveRouter continues to expand beyond the North American Tier 1s into international and enterprise markets, with the world’s first trial of 1.6Tbps in a router • Achieved a record shipping quarter for Routing and Switching, driven by the Data Center Out-of-band network management (DCOM) solution • Total shareholder return three-year CAGR of 18%1 • Repurchased ~1.0 million shares for $81.8 million under our three-year program (FY25-27) 1 Based on closing share price between 8/15/2022 to 8/14/2025 Achieving broad-based growth Prioritizing long term shareholder value Driving the pace of innovation

© Ciena Corporation 2025. All rights reserved. Proprietary Information.18 Q3 FY 2025 comparative financial highlights * Reconciliations of these non-GAAP measures to our GAAP results are included in the Appendix and in the press release for the relative period. Q3 FY 2025 Q3 FY 2024 Revenue $1,219.4M $942.3M Adjusted Gross Margin* 41.9% 43.7% Adjusted Operating Expense* $380.2M $336.0M Adjusted Operating Margin* 10.7% 8.0% Adjusted EBITDA* $158.0M $98.5M Adjusted EPS* $0.67 $0.35

© Ciena Corporation 2025. All rights reserved. Proprietary Information.19 Q3 FY 2025 comparative operating metrics Q3 FY 2025 Q3 FY 2024 Cash and investments $1.39B $1.21B Cash provided by (used in) operations $174M $(159)M Free cash flow $135M $(179)M DSO 88.0 100.0 Inventory turns 2.7 1.8 Net debt $204M $401M Gross leverage 2.81x 3.08x

© Ciena Corporation 2025. All rights reserved. Proprietary Information.20 Revenue by segment (Amounts in millions) Q3 FY 2025 Q3 FY 2024 Revenue %** Revenue %** Networking Platforms Optical Networking $815.5 66.9 $606.8 64.4 Routing and Switching 125.9 10.3 92.7 9.8 Total Networking Platforms 941.4 77.2 699.5 74.2 Platform Software and Services 90.0 7.4 83.2 8.9 Blue Planet Automation Software and Services 27.8 2.3 25.8 2.7 Global Services Maintenance Support and Training 80.7 6.6 74.4 7.9 Installation and Deployment 65.9 5.4 46.5 4.9 Consulting and Network Design 13.6 1.1 12.9 1.4 Total Global Services 160.2 13.1 133.8 14.2 Total $1,219.4 100.0 $942.3 100.0 * Reconciliations of these non-GAAP measures to GAAP results are included in the appendix to this presentation. ** Denotes % of total revenue

© Ciena Corporation 2025. All rights reserved. Proprietary Information.24 Economic considerations and assumptions in our 2025 outlook • We secure increased orders from Service Providers and from Cloud Providers as they continue to build their networks to meet the growing demand from Cloud and AI • We do not experience significant deferrals of delivery of forecasted orders or of our existing backlog • We are able to ramp capacity and deliver new products according to our roadmap and customer adoption of these products continues to be consistent with our expectations • Component suppliers deliver on their supply commitments consistent with our expectations and we do not encounter any substantial new supply disruptions that we cannot successfully mitigate • Given our distinct competitive and technology advantages, we continue to benefit disproportionately and gain market share Revenue AssumptionsBusiness Assumptions Profitability Assumptions • Operating expense increases due to our strong performance • We expect quarterly variability in gross margins due to product mix • We are able to achieve product cost reductions consistent with our past practices, particularly for our new product introductions • We will benefit from being first to market, delivering to customers new, differentiated products that provide more value • Macro environment does not significantly worsen or result in any adverse effects on our business, including with respect to our customers' capex levels, priorities or spending in our major geographies • Longer-term fundamental industry demand drivers – including increasing demand for bandwidth, adoption of cloud architectures, network automation requirements, and AI- related expansions – will cause customers to prioritize network capex to address this demand • Our business is not materially impacted by the imposition of tariffs or similar significant trade measures by the U.S. or other countries or other significant regulatory changes

© Ciena Corporation 2025. All rights reserved. Proprietary Information.25 Business outlook1 1 Projections or outlook with respect to future operating results are only as of September 4, 2025, the date presented on the related earnings call. Actual results may differ materially from these forward-looking statements. Ciena assumes no obligation to update this information, whether as a result of new information, future events or otherwise. Q4 FY 2025 Revenue $1.24B to $1.32B Adjusted Gross Margin 42% to 43% Adjusted Operating Expense $390M to $400M

© Ciena Corporation 2025. All rights reserved. Proprietary Information.27 Q3 FY 2025 Q2 FY 2025 Q1 FY 2025 Q4 FY 2024 Q3 FY 2024 GAAP gross profit $503,079 $452,838 $471,821 $460,022 $403,945 Share-based compensation-products 2,027 2,033 1,750 1,736 1,660 Share-based compensation-services 3,942 3,980 3,405 3,257 3,122 Amortization of intangible assets 2,232 2,232 2,233 2,764 2,764 Total adjustments related to gross profit 8,201 8,245 7,388 7,757 7,546 Adjusted (non-GAAP) gross profit $511,280 $461,083 $479,209 $467,779 $411,491 Adjusted (non-GAAP) gross profit percentage 41.9 % 41.0 % 44.7 % 41.6 % 43.7 % Gross Profit Reconciliation (Amounts in thousands)

© Ciena Corporation 2025. All rights reserved. Proprietary Information.28 Q3 FY 2025 Q2 FY 2025 Q1 FY 2025 Q4 FY 2024 Q3 FY 2024 GAAP operating expense $429,544 $419,996 $391,158 $400,812 $377,202 Share-based compensation-research and development 16,749 17,021 14,237 14,065 13,118 Share-based compensation-sales and marketing 13,277 13,649 11,597 11,168 10,315 Share-based compensation-general and administrative 11,008 11,341 9,827 10,842 9,257 Significant asset impairments and restructuring costs 1,770 1,948 1,544 2,605 1,361 Amortization of intangible assets 6,556 6,545 6,545 7,185 7,185 Total adjustments related to operating expense 49,360 50,504 43,750 45,865 41,236 Adjusted (non-GAAP) operating expense $380,184 $369,492 $347,408 $354,947 $335,966 Q3 FY 2025 Q2 FY 2025 Q1 FY 2025 Q4 FY 2024 Q3 FY 2024 GAAP income from operations $73,535 $32,842 $80,663 $59,210 $26,743 Total adjustments related to gross profit 8,201 8,245 7,388 7,757 7,546 Total adjustments related to operating expense 49,360 50,504 43,750 45,865 41,236 Total adjustments related to income from operations 57,561 58,749 51,138 53,622 48,782 Adjusted (non-GAAP) income from operations $131,096 $91,591 $131,801 $112,832 $75,525 Adjusted (non-GAAP) operating margin percentage 10.7 % 8.2 % 12.3 % 10.0 % 8.0 % Operating Expense Reconciliation (Amounts in thousands) Income from Operations Reconciliation (Amounts in thousands)

© Ciena Corporation 2025. All rights reserved. Proprietary Information.29 Q3 FY 2025 Q2 FY 2025 Q1 FY 2025 Q4 FY 2024 Q3 FY 2024 GAAP net income $50,308 $8,969 $44,572 $37,028 $14,230 Exclude GAAP provision for income taxes 15,511 10,047 24,022 10,993 2,125 Income before income taxes 65,819 19,016 68,594 48,021 16,355 Total adjustments related to income from operations 57,561 58,749 51,138 53,622 48,782 Loss on extinguishment and modification of debt — — 729 — — Adjusted income before income taxes 123,380 77,765 120,461 101,643 65,137 Non-GAAP tax provision on adjusted income before income taxes 27,144 17,108 26,501 22,361 14,330 Adjusted (non-GAAP) net income $96,236 $60,657 $93,960 $79,282 $50,807 Weighted average basic common shares outstanding 141,846 142,503 142,880 144,240 144,394 Weighted average diluted potential common shares outstanding(1) 144,499 144,972 145,944 146,487 145,361 Q3 FY 2025 Q2 FY 2025 Q1 FY 2025 Q4 FY 2024 Q3 FY 2024 GAAP diluted net income per potential common share $ 0.35 $ 0.06 $ 0.31 $ 0.25 $ 0.10 Adjusted (non-GAAP) diluted net income per potential common share $ 0.67 $ 0.42 $ 0.64 $ 0.54 $ 0.35 1. Weighted average dilutive potential common shares outstanding used in calculating Adjusted (non-GAAP) diluted net income per potential common share for the third quarter of fiscal 2025 includes 2.7 million shares underlying certain stock option and stock unit awards. Net Income Reconciliation (Amounts in thousands) Net Income per Common Share

© Ciena Corporation 2025. All rights reserved. Proprietary Information.30 Earnings Before Interest, Tax, Depreciation and Amortization (EBITDA) Q3 FY 2025 Q2 FY 2025 Q1 FY 2025 Q4 FY 2024 Q3 FY 2024 Net income (GAAP) $50,308 $8,969 $44,572 $37,028 $14,230 Add: Interest expense 22,806 21,697 22,918 24,990 24,401 Less: Interest and other income, net 15,090 7,871 11,578 13,801 14,013 Add: Loss on extinguishment and modification of debt — — 729 — — Add: Provision for income taxes 15,511 10,047 24,022 10,993 2,125 Add: Depreciation of equipment, building, furniture and fixtures, and amortization of leasehold improvements 26,866 25,092 24,679 23,849 22,981 Add: Amortization of intangible assets 8,788 8,777 8,778 9,949 9,949 EBITDA $109,189 $66,711 $114,120 $93,008 $59,673 Add: Share-based compensation expense 47,003 48,024 40,816 41,068 37,472 Add: Significant asset impairments and restructuring expense 1,770 1,948 1,544 2,605 1,361 Adjusted EBITDA $157,962 $116,683 $156,480 $136,681 $98,506 Earnings Before Interest, Tax, Depreciation and Amortization (EBITDA) (Amounts in thousands)