Ethernet vs. Carrier Ethernet: How do they differ? (original) (raw)

Article 4 of 6

Part of: The basics of Ethernet

Connectivity over longer distances and higher data rates are some of the major differences that separate Carrier Ethernet from traditional wired Ethernet.

Most people are familiar with Ethernet. In the home, Ethernet connects desktop computers and laptops to printers and routers. In the office, Ethernet connects computers to servers and the internet. Essentially, Ethernet is a LAN that connects devices via physical cables and carries data over a limited distance.

Carrier Ethernet, on the other hand, is a set of services that carry data over long distances. Network service providers offer carrier internet to connect geographically distributed facilities within an enterprise or connect enterprises to other enterprises and the internet. Enterprises can also take advantage of Carrier Ethernet capabilities to build networks and connect their facilities without relying on a network service provider.

While the word Ethernet appears in both terms, traditional Ethernet and Carrier Ethernet differ significantly.

What is Ethernet?

Ethernet is a LAN technology specified by ISO and IEEE wireless standards, which define types of cables, electrical signals, data formats and protocols that control data transfer between stations connected to the wire. ISO and IEEE defined the Ethernet standard using data formats that worked with LANs, such as maximum and minimum packet sizes and header and trailer formats. Each Ethernet standard, such as 802.3 and 802.3z, specifies cable lengths, transmission speeds and media type.

When it was developed in the 1970s, Ethernet was initially limited to a 10 Mbps data rate using coax cable and competed with other types of LAN technology, such as token ring. But Ethernet has proven to be reliable, efficient and less expensive than its competitors and is, by far, the dominant LAN technology today.

Ethernet segments are limited to lengths of 100 meters because stations connected to Ethernet share a communication medium. If two stations send messages at the same time, both signals distort and become unreadable. Stations detect the collision and retransmit the message, but they could fail to detect the error if they're physically located too far apart. The speed of light through the cable determines the maximum distance.

Network professionals can circumvent the 100-meter Ethernet length limit and build networks that span buildings or complexes by connecting individual segments with switches and routers. Building a network that spans longer distances requires the use of WAN services, like Carrier Ethernet.

What is Carrier Ethernet?

Carrier Ethernet is a set of services specified by MEF, an organization of service providers and equipment vendors that define services to connect Ethernet LANs within a metropolitan area. MEF developed Carrier Ethernet in response to the growing need to connect networks over larger areas.

Carrier Ethernet can connect distant Ethernet LANs like they are all part of a single bridged LAN. It can connect geographically distributed remote workers to databases or applications executing on servers as if they are located in a facility housing these services.

Carrier Ethernet services

Unlike the ISO and IEEE specifications, which define Ethernet standards with internal details, like voltage levels and cable length, the MEF specifications define Carrier Ethernet with an external view, looking at the provided services but not the details of how to provide them.

Service providers can use Carrier Ethernet to offer service-level agreements that guarantee higher data rates and quality of service (QoS) for voice, video, data and mobile services. Because defined services describe the service but not the underlying technology, service providers can choose from available wide area technologies to provide the level of service. Data transmission occurs by using transport technologies, like Synchronous Optical Network, Synchronous Digital Hierarchy, MPLS and other WAN technologies, that meet the necessary performance requirements.

Additionally, service providers use Carrier Ethernet to provide operations, administration and maintenance services, also known as OAM. Carriers use these management functions to monitor network performance and guarantee reliable network connectivity for customers.

Carrier Ethernet standards

MEF has developed standards for each Carrier Ethernet function. It's important for carriers to adhere to these standards to meet customer requirements for performance and reliability. Some vital techniques used to maintain reliability include quick detection of network faults and isolating faults and correction. Constant monitoring of throughput and QoS guarantees is also vital.

Carrier Ethernet has proven to be highly successful. Applications have developed to take advantage of its capabilities and will continue to use the technology due to its flexibility and reliability.