Ribbon Communications Inc.

Previous wording

*Tariffs.The United States has implemented, or threatened to implement, tariffs on products imported into the United States from numerous countries, including Mexico, Canada, China, Taiwan, Thailand and the European Union, amongst others. Many of these countries have implemented, or have threatened to implement, reciprocal tariffs in response. We maintain a global supply chain with our contract manufacturing partners located outside of the United States in several different countries. While the announced tariffs have not had a material impact on our business to date, the proposed tariffs, including exemptions under existing trade agreements or otherwise are continuing to evolve and could result in additional expenses for products we import into the United States. In addition, the economic uncertainty caused by the tariffs may result in customers delaying planned purchases of products and services. *

Current wording

*Tariffs.The United States has implemented, or indicated that it may or intends to implement, tariffs on products imported into the United States from numerous countries, including Mexico, Canada, China, Taiwan, Thailand and the European Union, amongst others. Many of these countries have implemented, or have threatened to implement, reciprocal tariffs in response. We maintain a global supply chain with our contract manufacturing partners located outside of the United States in several different countries. While the announced tariffs have not had a material impact on our business to date, the proposed tariffs, including exemptions under existing trade agreements or otherwise are continuing to evolve and could result in additional expenses for products we import into the United States. In addition, the economic uncertainty caused by the tariffs may result in customers delaying planned purchases of products and services. *

Previous wording

The Ongoing Wars in Israel and Ukraine. The uncertainty resulting from the wars in Israel and Ukraine, and the threat for expansion of one or both of these wars, could result in some of our customers delaying purchases from us. Further, a number of our employees in Israel are members of the military reserves and subject to immediate call-up in response to the war in Israel. Following the terrorist attacks in Israel in October 2023, a number of our employees have been activated for military duty and we expect that additional employees will also be activated if the war in Israel continues. While we have business continuity plans in place to address the military call-ups, it could affect the timing of projects in the short-term as the work is shifted to other team members both inside and outside of Israel.

Current wording

The Ongoing Wars in Israel and Ukraine. The uncertainty resulting from the ongoing wars in Israel and Ukraine, and the threat for expansion of one or both of these wars, could result in some of our customers delaying purchases from us. Further, a number of our employees in Israel are members of the military reserves and subject to immediate call-up in response to the war in Israel. Following the terrorist attacks in Israel in October 2023, a number of our employees have been activated for military duty and we expect that additional employees will also be activated if the war in Israel continues. While we have business continuity plans in place to address the military call-ups, it could affect the timing of projects in the short-term as the work is shifted to other team members both inside and outside of Israel.

Previous wording

Russia or provide any replacement parts in Russia. The sanctions continue to evolve and further changes in the current sanctions or trade restrictions could further limit our ability to sell products and services to customers in Russia, our ability to collect on outstanding accounts receivable from such customers, and our ability to repatriate funds. If we are further limited in our ability to sell products and services to Russia and other countries for an extended period, it could have a material impact on our financial results.

Current wording

The U.S. and other European countries have imposed sanctions and trade restrictions against Russia in connection with the war in Ukraine. These sanctions and restrictions currently prohibit our ability to sell hardware products in Russia or provide any replacement parts in Russia. The sanctions continue to evolve and further changes in the current sanctions or trade restrictions could further limit our ability to sell products and services to customers in Russia, our ability to collect on outstanding accounts receivable from such customers, and our ability to repatriate funds.

Previous wording

Inflation and Interest Rates. We continue to see near-term impacts on our business due to inflation, including ongoing global price pressures resulting in higher energy prices, component costs, freight premiums, and other operating costs above normal rates. Although headline inflation in the United States and Europe appears to be easing, core inflation (excluding food and energy prices) remains elevated and is a source of continued cost pressure on businesses and households. Interest rates remain high as central banks in developed countries attempt to subdue inflation while government deficits and debt remain at high levels in many global markets. However, since its peak in 2024, the Federal Reserve lowered the federal funds rate to its current target range of 4.25% to 4.50% as a result of indicators that inflation had made progress toward the Federal Reserve’s objective and labor market conditions had generally eased. Yet, the economic outlook remains uncertain, and the implications of current and future tariffs, higher government deficits and debt, tighter monetary policy, and potentially higher long-term interest rates may drive a higher cost of capital for our business.

Current wording

Inflation and Interest Rates. We continue to see near-term impacts on our business due to inflation, including ongoing global price pressures resulting in higher energy prices, component costs, freight premiums, and other operating costs above normal rates. Although headline inflation in the United States and Europe appears to be easing, core inflation (excluding food and energy prices) remains elevated and is a source of continued cost pressure on businesses and households. Interest rates remain high as central banks in developed countries attempt to subdue inflation while government deficits and debt remain at high levels in many global markets. However, since its peak in 2024, the Federal Reserve lowered the federal funds rate to its current target range of 4.00% to 4.25% as a result of indicators that inflation had made progress toward the Federal Reserve’s objective and labor market conditions had generally eased. Yet, the economic outlook remains uncertain, and the implications of current and future tariffs, higher government deficits and debt, tighter monetary policy, and potentially higher long-term interest rates may drive a higher cost of capital for our business.

Previous wording

We reported income from operations of $4.2 million and a loss from operations of $1.9 million for the three months ended June 30, 2025 and 2024, respectively. We reported a loss from operations of $15.4 million for each of the six months ended June 30, 2025 and 2024.

Current wording

We reported income from operations of $2.8 million and a loss from operations of $0.9 million for the three months ended September 30, 2025 and 2024, respectively. We reported a loss from operations of $12.6 million and $16.3 million for the nine months ended September 30, 2025 and 2024, respectively.

Previous wording

Our revenue was $220.6 million and $192.6 million in the three months ended June 30, 2025 and 2024, respectively. Our gross profit and gross margin were $109.3 million and 49.6%, respectively, in the three months ended June 30, 2025, and $97.9 million and 50.8%, respectively, in the three months ended June 30, 2024. The higher revenue in the three months ended June 30, 2025 compared to 2024 is due to $26.5 million of higher overall Cloud and Edge revenue and $1.5 million of higher IP Optical Networks sales. The higher Cloud and Edge revenue was attributable to $16.5 million of higher product sales and $10.8 million of higher sales of professional services, partially offset by $0.8 million of lower maintenance revenue. The higher IP Optical Networks revenue was primarily due to higher maintenance revenue. Our revenue was $401.9 million and $372.3 million in the six months ended June 30, 2025 and 2024, respectively. Our gross profit and gross margin were $191.7 million and 47.7%, respectively, in the six months ended June 30, 2025, and $189.8 million and 51.0%, respectively, in the six months ended June 30, 2024. The higher revenue in the six months ended June 30, 2025 compared to 2024 is due to $32.4 million of higher overall Cloud and Edge revenue, partially offset by $2.8 million of lower IP Optical Networks sales. The higher Cloud and Edge revenue was attributable to $18.8 million of higher sales of professional services and $16.9 million of higher product sales, partially offset by $3.3 million of lower maintenance revenue. The lower IP Optical Networks revenue was due to $6.6

Current wording

$5.0 million of higher professional services revenue. Our revenue was $617.2 million and $582.5 million in the nine months ended September 30, 2025 and 2024, respectively. Our gross profit and gross margin were $299.6 million and 48.5%, respectively, in the nine months ended September 30, 2025, and $299.4 million and 51.4%, respectively, in the nine months ended September 30, 2024. The higher revenue in the nine months ended September 30, 2025 compared to 2024 is due to $28.8 million of higher overall Cloud and Edge revenue and $5.9 million of higher IP Optical Networks sales. The higher Cloud and Edge revenue was attributable to $23.8 million of higher sales of professional services and $9.5 million of higher product sales, partially offset by $4.5 million of lower maintenance revenue. The higher IP Optical Networks revenue was due to $3.9 million of higher maintenance revenue and $3.4 million of higher sales of professional services, partially offset by $1.4 million of lower product revenue.

Previous wording

Revenue from our Cloud and Edge segment was $137.0 million and $110.6 million in the three months ended June 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $83.7 million and 61.1%, respectively, in the three months ended June 30, 2025, and $70.4 million and 63.7%, respectively, in the three months ended June 30, 2024. Revenue from our Cloud and Edge segment was $244.6 million and $212.2 million in the six months ended June 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $149.8 million and 61.2%, respectively, in the six months ended June 30, 2025, and $134.9 million and 63.6%, respectively, in the six months ended June 30, 2024.

Current wording

Revenue from our Cloud and Edge segment was $124.5 million and $128.1 million in the three months ended September 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $76.5 million and 61.5%, respectively, in the three months ended September 30, 2025, and $84.3 million and 65.9%, respectively, in the three months ended September 30, 2024. Revenue from our Cloud and Edge segment was $369.1 million and $340.3 million in the nine months ended September 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $226.3 million and 61.3%, respectively, in the nine months ended September 30, 2025, and $219.2 million and 64.4%, respectively, in the nine months ended September 30, 2024.

Previous wording

Revenue from our IP Optical Networks segment was $83.5 million and $82.1 million in the three months ended June 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $25.6 million and 30.6%, respectively, in the three months ended June 30, 2025, and $27.4 million and 33.4%, respectively, in the three months ended June 30, 2024. Revenue from our IP Optical Networks segment was $157.2 million and $160.1 million in the six months ended June 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $41.8 million and 26.6%, respectively, in the six months ended June 30, 2025, and $55.0 million and 34.3%, respectively, in the six months ended June 30, 2024.

Current wording

Revenue from our IP Optical Networks segment was $90.9 million and $82.2 million in the three months ended September 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $31.5 million and 34.6%, respectively, in the three months ended September 30, 2025, and $25.3 million and 30.8%, respectively, in the three months ended September 30, 2024. Revenue from our IP Optical Networks segment was $248.1 million and $242.2 million in the nine months ended September 30, 2025 and 2024, respectively. Gross profit and gross margin for this segment were $73.3 million and 29.5%, respectively, in the nine months ended September 30, 2025, and $80.2 million and 33.1%, respectively, in the nine months ended September 30, 2024.

Previous wording

Our operating expenses were $105.1 million and $99.8 million in the three months ended June 30, 2025 and 2024, respectively, and $207.1 million and $205.2 million in the six months ended June 30, 2025 and 2024, respectively. The increased operating expenses are primarily attributable to $3.9 million of legal and professional fees recorded in 2025 associated with contemplated corporate development activities, and slightly higher general and administrative expenses, partially offset by lower sales and marketing expense. Operating expenses for the three months ended June 30, 2025 included $6.0 million of amortization of acquired intangible assets, $3.9 million of acquisition-, disposal- and integration-related expense and $1.3 million of restructuring and related expense. Operating expenses for the three months ended June 30, 2024 included $6.5 million of amortization of acquired intangible assets, and $1.9 million of restructuring and related expense. Operating expenses for the six months ended June 30, 2025 included $12.1 million of amortization of acquired intangible assets, $3.9 million of acquisition-, disposal- and integration-related expense and $6.7 million of restructuring and related expense. Operating expenses for the six months ended June 30, 2024 included $13.2 million of amortization of acquired intangible assets, and $5.0 million of restructuring and related expense.

Current wording

Our operating expenses were $105.2 million and $110.5 million in the three months ended September 30, 2025 and 2024, respectively, and $312.3 million and $315.8 million in the nine months ended September 30, 2025 and 2024, respectively. The decreased operating expenses are primarily attributable to lower general and administrative expenses. Operating expenses for the three months ended September 30, 2025 included $5.9 million of amortization of acquired intangible assets, $0.4 million of acquisition-, disposal- and integration-related expense, and $3.5 million of restructuring and related expense. Operating expenses for the three months ended September 30, 2024 included $6.5 million of amortization of acquired intangible assets and $3.8 million of restructuring and related expense. Operating expenses for the nine months ended September 30, 2025 included $18.1 million of amortization of acquired intangible assets, $4.3 million of acquisition-, disposal- and integration-related expense, and $10.2 million of restructuring and related expense. Operating expenses for the nine months ended September 30, 2024 included $19.7 million of amortization of acquired intangible assets, and $8.8 million of restructuring and related expense.

Previous wording

We recorded stock-based compensation expense of $4.5 million and $3.5 million in the three months ended June 30, 2025 and 2024, respectively, and $8.8 million and $8.0 million in the six months ended June 30, 2025 and 2024, respectively. These amounts are included as components of both Cost of revenue and Operating expenses in our condensed consolidated statements of operations.

Current wording

We recorded stock-based compensation expense of $5.8 million and $4.0 million in the three months ended September 30, 2025 and 2024, respectively, and $14.6 million and $12.1 million in the nine months ended September 30, 2025 and 2024, respectively. These amounts are included as components of both Cost of revenue and Operating expenses in our condensed consolidated statements of operations.

Previous wording

See "Results of Operations" in this MD&A for a discussion of the changes in our revenue and expenses for three and six months ended June 30, 2025 compared to three and six months ended June 30, 2024.

Current wording

See "Results of Operations" in this MD&A for a discussion of the changes in our revenue and expenses for three and nine months ended September 30, 2025 compared to three and nine months ended September 30, 2024.

Previous wording

During the first quarter of 2025, our President and CEO approved a strategic restructuring program (the "2025 Restructuring Plan") that consists of workforce reductions in certain of our operating locations to correspond with current sales levels in those areas. Any potential positions eliminated in countries outside the United States are subject to local law and consultation requirements. In connection with the 2025 Restructuring Plan, we recorded restructuring and related expense of $0.2 million and $2.6 million in three and six months ended June 30,2025. We anticipate that we will record additional expense in 2025 for workforce reductions in connection with the 2025 Restructuring Plan.

Current wording

During the first quarter of 2025, our President and CEO approved a strategic restructuring program (as subsequently amended, the "2025 Restructuring Plan") that consists of workforce reductions in certain of our operating locations to correspond with current sales levels in those areas. The 2025 Restructuring Plan was amended in the third quarter of 2025 to reflect an increase in the scope of the proposed reductions. Any potential positions eliminated in countries outside the United States are subject to local law and consultation requirements. In connection with the 2025 Restructuring Plan, we recorded restructuring and related expense of $2.5 million and $5.1 million in three and nine

Previous wording

In February 2022, our Board of Directors approved a strategic restructuring program (the "2022 Restructuring Plan") to streamline our operations in order to support our investment in critical growth areas. The 2022 Restructuring Plan includes, among other things, charges related to a consolidation of facilities and a workforce reduction. Any positions eliminated in countries outside the United States are subject to local law and consultation requirements. In connection with the 2022 Restructuring Plan, we recorded restructuring and related expense of $1.2 million and

Current wording

In February 2022, our Board of Directors approved a strategic restructuring program (the "2022 Restructuring Plan") to streamline our operations in order to support our investment in critical growth areas. The 2022 Restructuring Plan includes, among other things, charges related to a consolidation of facilities and a workforce reduction. Any positions eliminated in countries outside the United States are subject to local law and consultation requirements. In connection with the 2022 Restructuring Plan, we recorded restructuring and related expense of $0.9 million and $5.2 million in the three and nine months ended September 30, 2025, respectively, for variable and other facilities-related costs. We anticipate that we will record approximately $1 million of expense in the remainder of 2025 related to the 2022 Restructuring Plan.

Previous wording

For facilities that are part of a restructuring plan, for which we have no intent or ability to enter into a sublease, we recognize accelerated rent amortization over the period from the date that we commence the plan to fully or partially vacate a facility through the final vacate date. We did not record accelerated rent amortization in the three and six months ended June 30, 2025 or 2024. We continue to evaluate our properties included in our restructuring plans for accelerated amortization and/or right-of-use asset impairment. We may incur additional expense in the future if we are unable to sublease other locations included in these initiatives.

Current wording

For facilities that are part of a restructuring plan, for which we have no intent or ability to enter into a sublease, we recognize accelerated rent amortization over the period from the date that we commence the plan to fully or partially vacate a facility through the final vacate date. We did not record accelerated rent amortization in the three and nine months ended September 30, 2025 or 2024. We continue to evaluate our properties included in our restructuring plans for accelerated amortization and/or right-of-use asset impairment. We may incur additional expense in the future if we are unable to sublease other locations included in these initiatives.

Previous wording

Revenue. Revenue for three and six months ended June 30, 2025 and 2024 was as follows (in thousands, except percentages):

Current wording

Revenue. Revenue for three and nine months ended September 30, 2025 and 2024 was as follows (in thousands, except percentages):

Previous wording

The increase in our product revenue in the three months ended June 30, 2025 compared to the three months ended June 30, 2024 was the result of $17 million of higher sales of our Cloud and Edge products, partially offset by a slight decrease in sales of IP Optical Networks products. The increase in our product revenue in the six months ended June 30, 2025 compared to the six months ended June 30, 2024 was the result of $17 million of higher sales of our Cloud and Edge products, partially offset by a $7 million decrease in sales of IP Optical Networks products. The increase in revenue from the sale of Cloud and Edge products was primarily attributable to U.S. service providers and Federal agencies. The decrease in sales of IP Optical Networks products was primarily due to lower sales in Eastern Europe, partially offset by higher sales in India and the United States.

Current wording

The decrease in our product revenue in the three months ended September 30, 2025 compared to the three months ended September 30, 2024 was the result of $7 million of lower sales of our Cloud and Edge products, partially offset by $5 million of higher sales of IP Optical Networks products. The increase in our product revenue in the nine months ended September 30, 2025 compared to the nine months ended September 30, 2024 was the result of $9 million of higher sales of our Cloud and Edge products, partially offset by a $1 million decrease in sales of IP Optical Networks products. For the three months ended September 30, 2025 compared to the prior year, the decrease in sales of Cloud and Edge products was primarily attributable to lower sales to enterprise customers, including Federal agencies. The increase in sales of IP Optical Networks products for the three months ended September 30, 2025 compared to the prior year was primarily due to higher sales in India and the region of Europe, the Middle East and Africa (“EMEA”), partially offset by lower sales in the United States. For the nine months ended September 30, 2025 compared to the prior year, the increase in revenue from the sale of Cloud and Edge products was primarily attributable to U.S. service providers and enterprise customers. The increase in sales of IP Optical Networks products for the nine months ended September 30, 2025 compared to the prior year was primarily due to higher sales in India and EMEA, partially offset by lower sales in the United States and Eastern Europe.

Previous wording

Revenue from sales to enterprise customers was 34% and 38% of our product revenue in the three months ended June 30, 2025 and 2024, respectively. These sales were made through both our direct sales team and indirect sales channel partners. Revenue from sales to enterprise customers was 32% and 41% of our product revenue in the six months ended June 30, 2025 and 2024, respectively. The decrease in enterprise sales primarily reflects lower sales of our products to Federal agencies and other enterprise customers.

Current wording

Revenue from sales to enterprise customers was 34% and 36% of our product revenue in the three months ended September 30, 2025 and 2024, respectively. These sales were made through both our direct sales team and indirect sales channel partners. Revenue from sales to enterprise customers was 32% and 39% of our product revenue in the nine months ended September 30, 2025 and 2024, respectively. The decrease in enterprise sales primarily reflects lower sales of our products to Federal agencies and other enterprise customers.

Previous wording

Revenue from indirect sales through our channel partner program was 34% and 32% of our product revenue in the three months ended June 30, 2025 and 2024 and 31% and 41% of our product revenue in the six months ended June 30, 2025 and 2024, respectively. The decrease in channel sales in the six months ended June 30, 2025 primarily reflects lower sales of products to Federal agencies and other enterprise customers.

Current wording

Revenue from indirect sales through our channel partner program was 26% and 34% of our product revenue in the three months ended September 30, 2025 and 2024 and 29% and 38% of our product revenue in the nine months ended September 30, 2025 and 2024, respectively. The decrease in channel sales in the nine months ended September 30, 2025 primarily reflects lower sales of products to Federal agencies and other enterprise customers.

Previous wording

Service revenue for the three and six months ended June 30, 2025 and 2024 was comprised of the following (in thousands, except percentages):

Current wording

Service revenue for the three and nine months ended September 30, 2025 and 2024 was comprised of the following (in thousands, except percentages):

Previous wording

Segment service revenue for the three and six months ended June 30, 2025 and 2024 was comprised of the following (in thousands):

Current wording

Segment service revenue for the three and nine months ended September 30, 2025 and 2024 was comprised of the following (in thousands):

Previous wording

Total service revenue was higher in the three and six months ended June 30, 2025 compared to the same periods in 2024 due to increased revenue in both of our segments. Total service revenue for the three months ended June 30, 2025 compared to 2024 increased by $10 million and $2 million in our Cloud and Edge and IP Optical Networks segments, respectively. Total service revenue for the six months ended June 30, 2025 compared to 2024 increased by $15 million and $4 million in our Cloud and Edge and IP Optical Networks segments, respectively.

Current wording

Total service revenue was higher in the three and nine months ended September 30, 2025 compared to the same periods in 2024 primarily due to increased professional services revenue in both of our segments. Total service revenue for the three months ended September 30, 2025 compared to 2024 increased by $4 million and $3 million in our Cloud and Edge and IP Optical Networks segments, respectively. Total service revenue for the nine months ended September 30, 2025 compared to 2024 increased by $19 million and $7 million in our Cloud and Edge and IP Optical Networks segments, respectively.

Previous wording

Maintenance revenue was relatively flat in the three and six months ended June 30, 2025 compared to the same periods in 2024 due to lower revenue in our Cloud and Edge segment, partially offset by higher revenue in our IP Optical Networks segment. The decrease in Cloud and Edge maintenance revenue is due to modestly lower renewal rates from decommissioning some older legacy equipment with several customers. The higher maintenance revenue in our IP Optical Networks segment is due to the effect of cumulative growth in product revenues over the years leading to a larger Installed Base that requires our ongoing support primarily in North America and Europe.

Current wording

Maintenance revenue was relatively flat in the three and nine months ended September 30, 2025 compared to the same periods in 2024 due to lower revenue in our Cloud and Edge segment, partially offset by higher revenue in our IP Optical Networks segment. The decrease in Cloud and Edge maintenance revenue is due to modestly lower renewal rates from decommissioning some older legacy equipment with several customers. The higher maintenance revenue in our IP Optical Networks segment is due to the effect of cumulative growth in product revenues over the years leading to a larger Installed Base that requires our ongoing support primarily in North America and Europe.

Previous wording

Professional services revenue was higher in the three and six months ended June 30, 2025 compared to the same periods in 2024 due to growth in both of our segments. Our Cloud and Edge segment’s growth was due to sales of professional services to U.S. service providers, primarily for voice modernization projects with Verizon. Our IP Optical

Current wording

Professional services revenue was higher in the three and nine months ended September 30, 2025 compared to the same periods in 2024 due to growth in both of our segments. Our Cloud and Edge segment’s growth was due to sales of professional services to U.S. service providers, primarily for voice modernization projects with Verizon. Our IP Optical Networks segment experienced growth of sales of services primarily in EMEA, India, and North America.

Previous wording

The following customer contributed 10% or more of our revenue in the three and six months ended June 30, 2025 and 2024:

Current wording

The following customers contributed 10% or more of our revenue in the three and nine months ended September 30, 2025 and 2024:

Previous wording

Revenue earned from customers domiciled outside the United States was 47% and 58% in the three months ended June 30, 2025 and 2024, respectively, and 51% and 59% of revenue in the six months ended June 30, 2025 and 2024, respectively. Our U.S. revenue is increasing due to higher sales into the U.S. market from both of our segments. Due to the timing of project completions, we expect that the domestic and international components as a percentage of our revenue may fluctuate from quarter to quarter and year to year.

Current wording

Revenue earned from customers domiciled outside the United States was 55% and 48% in the three months ended September 30, 2025 and 2024, respectively, and 52% and 55% of revenue in the nine months ended September 30, 2025 and 2024, respectively. Our U.S. revenue is increasing due to higher sales into the U.S. market from our Cloud & Edge segment. Due to the timing of project completions, we expect that the domestic and international components as a percentage of our revenue may fluctuate from quarter to quarter and year to year.

Previous wording

Our deferred product revenue was $12 million and $14 million at June 30, 2025 and December 31, 2024, respectively. Our deferred service revenue was $135 million and $126 million at June 30, 2025 and December 31, 2024, respectively. Our deferred revenue balance may fluctuate as a result of the timing of revenue recognition, customer payments, maintenance contract renewals, contractual billing rights and maintenance revenue deferrals included in multiple element arrangements.

Current wording

Our deferred product revenue was $8 million and $14 million at September 30, 2025 and December 31, 2024, respectively. Our deferred service revenue was $128 million and $126 million at September 30, 2025 and December 31, 2024, respectively. Our deferred revenue balance may fluctuate as a result of the timing of revenue recognition, customer payments, maintenance contract renewals, contractual billing rights and maintenance revenue deferrals included in multiple element arrangements.

Previous wording

We expect that our total revenue in 2025 will increase compared to our revenue in 2024 due to growth in Cloud & Edge segment sales, particularly with the increased purchases from Verizon as part of a voice modernization project, as well as growth in IP Optical segment sales. From a regional perspective, we anticipate continued IP Optical revenue growth in 2025 from North America, EMEA and India. In the Cloud & Edge segment, we expect continued revenue growth from Enterprise customers, as well as from higher U.S. service provider spending.

Current wording

We expect that our total revenue in 2025 will increase compared to our revenue in 2024 due to growth in Cloud & Edge segment sales, particularly with the increased purchases from Verizon as part of a voice modernization project, as well as growth in IP Optical segment sales. From a regional perspective, we anticipate continued IP Optical revenue growth in 2025 from EMEA and India. In the Cloud & Edge segment, we expect continued revenue growth from enterprise customers, as well as from higher U.S. service provider spending.

Previous wording

Cost of Revenue/Gross Margin. Our cost of revenue consists primarily of amounts paid to third-party manufacturers for purchased materials and services, royalties, amortization of acquired technology, inventory valuation adjustments, warranty costs, and manufacturing and services personnel and related costs. Our cost of revenue, gross profit and gross margin for the three and six months ended June 30, 2025 and 2024 were as follows (in thousands, except percentages):

Current wording

Cost of Revenue/Gross Margin. Our cost of revenue consists primarily of amounts paid to third-party manufacturers for purchased materials and services, royalties, amortization of acquired technology, inventory valuation adjustments, warranty costs, and manufacturing and services personnel and related costs. Our cost of revenue, gross profit and gross margin for the three and nine months ended September 30, 2025 and 2024 were as follows (in thousands, except percentages):

Previous wording

Our segment cost of revenue, gross profit and gross margin for the three and six months ended June 30, 2025 and 2024 were as follows (in thousands, except percentages):

Current wording

Our segment cost of revenue, gross profit and gross margin for the three and nine months ended September 30, 2025 and 2024 were as follows (in thousands, except percentages):

Previous wording

Our gross margin was lower as compared to 2024 with a 1% decrease overall in the three months ended June 30, 2025 and a 3% decrease overall in the six months ended June 30, 2025 as a result of lower margins in both of our segments.

Current wording

Our overall gross margin in 2025 was lower as compared to 2024, with a 200 basis point decline in the three months ended September 30, 2025 and a 290 basis point decline in the nine months ended September 30, 2025.

Previous wording

The lower margin in the six months ended June 30, 2025 in our IP Optical segment was due to regional mix primarily related to lower sales in Eastern Europe and higher sales in India. The lower margin in our Cloud and Edge segment was primarily attributable to product mix on sales to service providers and enterprise customers, as well as the effect of higher sales of hardware products and professional services, both of which contribute lower gross margins than our software products.

Current wording

Gross margin for our IP Optical segment was higher in the three months ended September 30, 2025 as compared to the prior year by 380 basis points due to favorable regional mix. Gross margin for our IP Optical segment in the nine months ended September 30, 2025 compared to 2024 was lower by 360 basis points also due to regional mix primarily related to lower sales in the United States and Eastern Europe and higher sales in India. The lower gross margin in our Cloud and Edge segment for the three and nine months ended September 30, 2025 of 440 and 310 basis points, respectively, was attributable to product mix on sales to service providers and enterprise customers, as well as the effect of higher sales of hardware products and professional services, both of which contribute lower gross margins than our software products.

Previous wording

Research and Development. R&D expenses consist primarily of salaries and related personnel expenses and prototype costs for the design, development, testing, and enhancement of our products. R&D expenses for the three and six months ended June 30, 2025 and 2024 were as follows (in thousands, except percentages):

Current wording

Research and Development. R&D expenses consist primarily of salaries and related personnel expenses and prototype costs for the design, development, testing, and enhancement of our products. R&D expenses for the three and nine months ended September 30, 2025 and 2024 were as follows (in thousands, except percentages):

Previous wording

Our IP Optical Networks R&D investment is focused on significantly expanding our portfolio of IP Routing solutions, adding additional features and capabilities to our Optical Transport portfolio, and supporting features in our next generation SDN management and orchestration platform.

Current wording

Our IP Optical Networks R&D investment is focused on expanding our portfolio of IP Routing solutions, adding additional features and capabilities to our Optical Transport portfolio, and supporting features in our next generation SDN management and orchestration platform.

Previous wording

Sales and Marketing Expenses. Sales and marketing expenses consist primarily of salaries and related personnel costs, commissions, travel and entertainment expenses, promotions, customer trial and evaluations inventory and other marketing and sales support expenses. Sales and marketing expenses for the three and six months ended June 30, 2025 and 2024 were as follows (in thousands, except percentages):

Current wording

Sales and Marketing Expenses. Sales and marketing expenses consist primarily of salaries and related personnel costs, commissions, travel and entertainment expenses, promotions, customer trial and evaluations inventory and other marketing and sales support expenses. Sales and marketing expenses for the three and nine months ended September 30, 2025 and 2024 were as follows (in thousands, except percentages):

Previous wording

The decrease in sales and marketing expenses in 2025 as compared to 2024 was primarily due to lower commissions, partially offset by higher travel expenses.

Current wording

The decrease in sales and marketing expenses in the nine months ended September 30, 2025 as compared to 2024 was primarily due to lower commissions, partially offset by higher travel expenses.

Previous wording

General and Administrative Expenses. General and administrative expenses consist primarily of salaries and related personnel costs for executive and administrative personnel, and audit, legal and other professional fees. General and administrative expenses for the three and six months ended June 30, 2025 and 2024 were as follows (in thousands, except percentages):

Current wording

General and Administrative Expenses. General and administrative expenses consist primarily of salaries and related personnel costs for executive and administrative personnel, and audit, legal and other professional fees. General and administrative expenses for the three and nine months ended September 30, 2025 and 2024 were as follows (in thousands, except percentages):

Previous wording

The increase in general and administrative expenses in the three and six months ended June 30, 2025 compared to the three and six months ended June 30, 2024 was primarily attributable to higher employee related costs and litigation expenses.

Current wording

The decrease in general and administrative expenses in the three and nine months ended September 30, 2025 compared to the three and nine months ended September 30, 2024 was primarily attributable to lower litigation expenses, partially offset by higher employee related costs.

Previous wording

Amortization of Acquired Intangible Assets included in Operating expenses. Amortization of acquired intangible assets included in Operating expenses ("Opex Amortization") for the three and six months ended June 30, 2025 and 2024 was as follows (in thousands, except percentages):

Current wording

Amortization of Acquired Intangible Assets included in Operating expenses. Amortization of acquired intangible assets included in Operating expenses ("Opex Amortization") for the three and nine months ended September 30, 2025 and 2024 was as follows (in thousands, except percentages):

Previous wording

Opex Amortization was lower for the three and six months ended June 30, 2025 compared to the three and six months ended June 30, 2024. We record our amortization in relation to expected future cash flows rather than on a straight-line basis. Accordingly, such expense may vary from one period to the next.

Current wording

Opex Amortization was lower for the three and nine months ended September 30, 2025 compared to the three and nine months ended September 30, 2024. We record our amortization in relation to expected future cash flows rather than on a straight-line basis. Accordingly, such expense may vary from one period to the next.

Previous wording

We recorded $3.9 million of acquisition-, disposal- and integration-related expenses in the three and six months ended June 30, 2025 consisting of legal and professional fees associated with contemplated corporate development activities. We recorded no such expenses in 2024.

Current wording

We recorded $0.4 million and $4.3 million of acquisition-, disposal- and integration-related expenses in the three and nine months ended September 30, 2025, respectively, consisting of legal and professional fees associated with contemplated corporate development activities. We recorded no such expenses in 2024.