CableLabs’ latest DOCSIS® 4.0 Interop·Labs event marked a major milestone for broadband technology — one that pushes the limits of aggregate downstream capacity and demonstrates the collaborative strength of the DOCSIS ecosystem.

The interop followed closely on the heels of a highly successful SCTE TechExpo25 in Washington, D.C., where suppliers showcased early demonstrations of DOCSIS 4.0 technology in action. Some of those same demos were shipped straight from the TechExpo show floor to CableLabs headquarters in Colorado for the interop event, ensuring continuity and real-world validation.

Leading suppliers convened Oct. 20–23 for the 14th DOCSIS 4.0 interop, working to verify equipment interoperability and expand the focus beyond modem performance. This time, attention turned to increasing aggregate capacity — the total bandwidth shared among groups of homes — far beyond what any single modem can achieve.

Increasing Aggregate Capacity: Beyond a Single Modem

The latest advances showcased a critical leap: the capability to boost aggregate speed. This wasn’t about the performance of a single modem but, instead, the collective capacity available to a group of homes served by a single fiber node.

A 2x2 Remote PHY Device (RPD) allows one physical fiber node to behave like two virtual nodes. A 2x2 RPD is capable of providing full spectrum service to up to two downstream service groups and 2 upstream service groups. In practice, this means an operator can effectively double the capacity of a traditional 1x1 node.

To handle this increased throughput, suppliers demonstrated 25 Gigabit Ethernet (GbE) links connecting fiber nodes to the CCAP-Core — a substantial upgrade from the standard 10 GbE links. The result: the increased DOCSIS 4.0 bandwidth is available to be shared across smaller service groups, enabling better performance and a foundation for next-generation multi-gigabit service tiers.

Innovation Through Collaboration

While the technology took center stage, the underlying story was one of collaboration. The event’s strong turnout underscored the excitement and commitment of industry stakeholders, which included many CableLabs member companies.

Nine modem suppliers — competitors in the marketplace — worked side by side to ensure that when DOCSIS 4.0 technology is deployed, it will perform reliably across the ecosystem. Each supplier brought its own hardware, firmware and feature optimizations — a combination of approaches that drove rich discussions and technical progress.

The supplier participation was impressive:

• CCAP-Cores: CommScope, Harmonic and Vecima
• Remote PHY Devices (RPDs): Calian, CommScope, Harmonic and Vecima
• Cable modems: Arcadyan, Askey, Gemtek, Hitron, Sagemcom, Sercomm, Ubee, Vantiva and WNC each brought multiple models.
• Chipmakers: Broadcom and MaxLinear provided engineering support.

With three cores in play, participants dived deep into DOCSIS 4.0’s multi-channel management — the real-time coordination of upstream and downstream channels across different parts of the RF spectrum. Each supplier’s goal was the same: to fine-tune performance and differentiate in a competitive market while ensuring seamless interoperability across all vendor combinations.

This breadth of representation reinforced that DOCSIS 4.0 is not just a specification — it’s a fully functioning, multi-vendor ecosystem.

DOCSIS 3.1 Plus: Bridging the Path to DOCSIS 4.0 Networks

The event also featured several DOCSIS 3.1+ modems — a key stepping-stone technology in the evolution of DOCSIS technology.

DOCSIS 3.1+ technology expands support for additional Orthogonal Frequency-Division Multiplexing (OFDM) channels, unlocking higher downstream speeds while maximizing the value of existing plant investments.

These aren’t theoretical gains — they were tested and verified in real time during the interop. Operators are already exploring how DOCSIS 3.1+ fits into their near-term deployment strategies, offering a cost-effective way to deliver multi-gigabit services today, while preparing for DOCSIS 4.0 networks tomorrow.

This spirit of cooperation is shaping the next phase of broadband evolution. By solving interoperability challenges together, suppliers are accelerating deployment timelines, simplifying operator adoption and ultimately delivering better experiences for consumers.

Looking Ahead: From Lab to Live Network

With this interop’s success, the message was clear: the DOCSIS community is uniting to deliver faster, higher-capacity broadband experiences to customers everywhere.

The event was another benchmark for the broadband industry’s future, offering further proof that multi-vendor DOCSIS 4.0 systems can deliver at scale. The next steps include refining firmware for even greater efficiency, expanding field trials and building the migration path toward commercial deployment.

With diverse vendor participation and clear proof of the technology’s capabilities, the path to multi-gigabit broadband has never been clearer.

CableLabs will host another DOCSIS 4.0 Interop·Labs event the week of Dec. 9, and we invite our member operators and the vendor community to join us and witness the next wave of innovation firsthand.

And don’t forget — registration is now open for the upcoming CableLabs Tech Summit, happening April 27–30, 2026, in Colorado. Built around the Technology Vision, Tech Summit is where the broadband industry comes together to align on the most critical areas shaping the future of connectivity — from strategic direction to technical execution, vendor collaboration and peer exchange.

Join us as we build a faster, smarter future of connectivity — together.