Carrier Ethernet - Background

Background

Ethernet has a long history. It has become dominant in enterprise networks. This dominance has led to high production-volume components, which in turn have allowed extremely low cost per bit. Likewise Ethernet has a long history of re-inventing itself. From the original copper coaxial cable format ("thicknet") it has extended its scope to nearly all copper, optical fiber and wireless physical media. Bit rates have continued to increase, traditionally growing tenfold each time a new rate is defined. Gigabit Ethernet interfaces are widely deployed in PCs and servers, and 10 Gbit/s in local area network (LAN) backbones. Rates up to 100 Gigabit Ethernet were standardized in 2010 and 2011.

Ethernet's dominance is partly attributed to the simple advantages for the industry of adopting a single standard to drive up volumes and drive down prices. In part, it is also due to ease of deployment, using its ability to self-configure based on the key concepts of “learning bridge” (flooding, and associating learned destination addresses with bridge ports) and "spanning tree protocol" (the protocol used for avoiding bridging loops).

Historically, competing protocols and cabling have been created in order to access higher speed devices than contemporary Ethernet-connected devices handled at an affordable price. Examples include FireWire and Light Peak. One motive to create competing standards has been to drive down the price of comparable-speed Ethernet devices. Once this purpose is achieved, competing standards tend to disappear or be confined to very specialized niches.

Ethernet is a fairly simple protocol which has scaled to hundreds of thousands of times faster speeds and consistently been able to adapt to meet the needs and demands of new markets. For example, time domain capabilities are being added to IEEE 802.3 Ethernet to support IEEE 802.1 Audio Video Bridging (AVB), and these capabilities will be applicable to time sensitive carrier applications likewise IEEE 1588.

Customer LAN networks are increasingly connected to wide-area telecommunications networks over Ethernet interfaces or to devices that bridge digital subscriber line (DSL) or wireless to these. Moreover, customers are familiar with the capabilities of Ethernet networks, and would like to extend these capabilities to multi-site networks. Meanwhile the needs of such networks have expanded to include many services previously handled only on the LAN or by specialized connections, notably video and backup. It is not practical to expand most small networks beyond 1G or at most 2G (dual teaming gigabit) capacity per segment, since the bottleneck remains in the wide area links to other offices and online services.