The cable industry is moving away from the old, central CMTS architecture and hardware. The new paradigm is built around virtualization. Everything is data, and generic hardware can handle it economically. The headend is no longer a specialized box that’s hard to expand. An important part of this shift is Distributed Access Architecture, or DAA. The DAA approach deals better with the challenges of rapidly expanding customer demand. Let’s take a look at these challenges and how the new architecture helps to meet them.

Equipment cost

Cable information, whether its voice, video, or data, can all be handled as IP packets. Only when these signals are converted to RF for last-mile delivery do they stop being pure digital data. Distributed architecture, with Remote PHY or Remote MAC/PHY, moves the physical layer out of the central office. What’s left is just a data center that can run on generic computer hardware. Even switching and routing functions can be virtualized. Edge servers can bring cached data closer to the customer.

The benefit to the bottom line is huge. Off-the-shelf computing equipment is less expensive than a dedicated CMTS. Many vendors compete on price and performance, so there’s no risk of vendor lock-in. Upgrades are easy, and leasing options eliminate the problem of what to do with outdated equipment. There are many options for hardware maintenance by in-house teams or contracted services.


Each customer wants better data speed, while the number of endpoints keeps growing. Competing technologies, such as 5G, promise ever higher speeds. This puts a double demand on bandwidth. Reducing the amount of RF cable needed is the key. Shorter cable connections mean less noise and attenuation. With DAA, fiber networks and other high-speed technologies carry the data closer to the customer’s endpoint. The most popular option currently is the deployment of Remote PHY nodes connected by fiber to the CCAP.

Fiber-optic lines are comparatively inexpensive to install and maintain. As bandwidth demands grow, more can be added along with new nodes where they’re needed most. Delivering more data at higher speeds is an achievable goal.


What many customers need, though they may not realize it, isn’t so much higher speed as reduced latency. They aren’t necessarily pushing through large amounts of data, but they want instantaneous responses. The gaming market is a clear example of this requirement. A typical online game sends and receives short data packets, but a significant turnaround time equals a slow reaction time and can ruin a player’s performance.

Other applications, such as video conferencing, require both decent bandwidth and low latency. Good bandwidth allows high resolution and frame rates. Minimizing latency can be an even more important requirement since perceptible delays destroy the feeling of real-time conversation. Moving equipment closer to the customer shrinks those delays.

Physical plant

Growing customer demand means more equipment, placing a growing burden on its physical environment. When everything is centralized, it takes up more space. There must be the installation of more racks, and more power has to be delivered to one place. The space has to be kept at a reasonable temperature.

Conversion to and from RF signals is a significant part of the requirement. Each physical cable connection takes up a certain irreducible amount of space and adds to the installation’s complexity. DAA moves this out of the central office. The processing hardware can be distributed over multiple locations. Parts of the architecture can be moved to cloud servers, taking them completely out of on-premises physical requirements.

Cable operators need to keep their networks up to date so they can meet customer demands and thrive in a competitive market. Contact us to learn how our expertise can help to achieve this.