RBBN · CIK 0001708055
What Ribbon Communications Inc. told the SEC could break it.
Ribbon's register concentrates at both ends of its business. On the demand side, a few customers carry it — the top five were about 41% of 2025 revenue, with Verizon alone roughly 17% — so losing any would materially hurt results. On the supply side, certain components and third-party software licenses are single-sourced, leaving a supplier or subcontractor failure able to delay product delivery, and it buys materials and components from Mexico, Malaysia, Thailand, Israel, China and elsewhere, exposing it to tariffs and trade restrictions. It also flags a significant Israel-based workforce, so the region's ongoing war and political-military conditions could directly disrupt operations.
4 self-disclosed vulnerabilities, pulled from its own filings, each in the company’s words, with the source. This is the risk register almost nobody reads.
In its own words
What could break it.
Customer concentration
- top five customers ~41% of revenuehigh
Ribbon depends on a few key customers — its top five contributed about 41% of revenue in 2025 (with Verizon alone ~17%) — so loss of any could materially hurt results.
“One customer, Verizon, contributed approximately 17% of our revenue in the year ended December 31, 2025. Our top five customers contributed approximately 41% of our revenue in 2025.”
SEC filing →As of 2026
Sole-source dependency
- single-source components and third-party software licenseshigh
Certain components and third-party software licenses in Ribbon's products are single-sourced; a supplier or subcontractor failure could delay product delivery and hurt revenue.
“Certain components and software licenses from third parties used in Ribbon's products are procured from single sources of supply. The failure of a supplier, including a subcontractor, to deliver on schedule could delay or interrupt Ribbon's delivery of products and thereby materially adversely affect Ribbon's revenue and operating results.”
SEC filing →As of 2026
Geographic concentration
- significant Israel-based workforce amid regional conflictmedium
Ribbon has a significant number of employees in Israel, so the ongoing war and political/military conditions there could directly disrupt its operations.
“We have a significant number of employees located in Israel. As a result, political, economic and military conditions in Israel may directly affect our business.”
Regulatory & policy
- tariff/trade exposure on foreign-sourced components (Mexico, Malaysia, Thailand, Israel, China)medium
Ribbon manufactures appliance products and buys raw materials/components from Mexico, Malaysia, Thailand, Israel, China and other countries, exposing it to tariffs, trade restrictions and retaliatory 'trade wars' that could raise costs.
“We manufacture certain of our appliance products and purchase a portion of our raw materials and components from suppliers in Mexico, Malaysia, Thailand, Israel, China and other foreign countries.”
The hidden graph
Who it depends on, and who depends on it.
Relationships surfaced from filings, including ones disclosed by the other side, which is how the non-obvious ones come to light.
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