By: John Shepler

Coaxial cable, commonly used by cable providers, was once thought to be outdated. People questioned its capacity for handling numerous channels and high internet speeds. However, it turns out coaxial cable can handle significantly more data than initially believed, reaching speeds up to 10 Gbps.

Fiber Optic Integration

The remarkable 10 Gbps speed, comparable to fiber optic standards, is achieved through a hybrid system. While users only see the coaxial cable connecting their modem, it’s just a small segment of the infrastructure. Beyond that, the connection transitions to a metropolitan fiber optic network. This hybrid fiber-copper (HFC) network allows for high-speed data transmission.

The Crucial Device

With the infrastructure capable of 10 Gbps speeds, the final component is an interface that can transmit and receive data on the HFC network, delivering a 10 Gbps Ethernet connection to the user. This is where the DOCSIS 3.1 Cable Modem comes in.

DOCSIS (Data Over Cable Service Interface Specification) is a set of standards defining how to utilize existing cable TV channels for high-speed data without affecting television broadcasts. Developed by CableLabs and backed by numerous equipment manufacturers, DOCSIS has undergone several iterations since its inception in 1997.

The latest version, DOCSIS 3.1, enables speeds of at least 10 Gbps downstream and 1 Gbps upstream, a significant improvement over previous versions. Additionally, it’s backward compatible, allowing for smooth integration with existing cable systems. The widespread adoption of DOCSIS 3.1 relies on cable operators upgrading their equipment and providing compatible modems.

The Rise of High Bandwidth Demand

The adoption of DOCSIS 3.1 by cable companies is inevitable due to the increasing demand for bandwidth. Competitors like Verizon, with their FiOS fiber-to-the-premises (FTTP) system, and Google Fiber are putting pressure on traditional cable providers. By adopting DOCSIS 3.1, cable companies can compete by offering gigabit and 10-gigabit speeds without a complete infrastructure overhaul.

Comcast, a major cable provider, recognizes this trend and plans to implement DOCSIS 3.1 across its entire service area soon.

Comparison to SONET and Ethernet over Fiber

It’s important to note that DOCSIS 3.1 differs significantly from SONET and Ethernet over Fiber in terms of technology, performance standards, and target audiences.

SONET, initially designed for telephone networks, uses fiber optic cables to transmit data. As bandwidth needs grew, it was adapted for business use, offering speeds from 155 Mbps to 40 Gbps.

Carrier Ethernet, directly compatible with Ethernet networks used in most businesses, comes in both copper and fiber optic implementations. Ethernet over Fiber is gaining popularity, offering speeds ranging from 10 Mbps to 100 Gbps.

Cable DOCSIS, SONET, and Fiber Ethernet: A Comparative Analysis

SONET and Ethernet over Fiber (EoF) rely solely on fiber optic connections, while cable utilizes existing coaxial connections. This gives cable an advantage in terms of accessibility and installation speed. However, this advantage is diminishing as fiber optic networks expand.

Cable seemingly holds a cost advantage, but this is more related to the service type than the technology. Google Fiber, for example, offers fiber optic internet at prices comparable to cable.

SONET and EoF, considered premium business services, typically include Service Level Agreements (SLAs) guaranteeing specific performance and uptime. Cable, a “best effort” service, lacks such guarantees.

SONET and EoF offer dedicated bandwidth, meaning the contracted speed is always available. Cable internet, a shared service, can lead to fluctuating speeds depending on network traffic.

Lastly, SONET and EoF are symmetrical, providing equal upload and download speeds. Conversely, cable internet is asymmetrical, with download speeds often 10 times faster than upload speeds.

Making the Right Choice

Cable internet suits typical consumer and small business needs, primarily focused on downloads. The shared bandwidth and reliability might be sufficient considering the cost-effectiveness.

However, businesses relying heavily on large file transfers, cloud-based services, or requiring high uptime should consider SONET or Ethernet over Fiber. Recent years have seen a significant price drop for both, with EoF emerging as a cost-effective option for high-performance requirements.

Note: Products with the humorous theme “Wan Man” shown on this page are available through the Gigapacket Zazzle Store.