This dominance has led to high production-volume components, which in turn have allowed extremely low cost per bit.
Gigabit Ethernet interfaces are widely deployed in PCs and servers, and 10 Gbit/s in local area network (LAN) backbones.
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.
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.
The principal concept was to bring the simplicity and cost model of Ethernet to the wide area network.
EPL provides a point-to-point Ethernet virtual connection (EVC) between a pair of dedicated user–network interfaces (UNIs), with a high degree of transparency.
Some implementations tunnel most Ethernet Layer 2 control protocols (L2CPs) except for some link-layer L2CPs such as IEEE 802.3x pause frames.
Point-to-point Ethernet links are carried over SDH/SONET networks, making use of virtual concatenation (ITU-T G.707) and LCAS (Link Capacity Adjustment Scheme - ITU-T G.7042) to create an appropriate size carrier bundle, of the Generic Framing Procedure of SDH equipment, and takes advantage of the management and recovery features of SDH to provide high availability and resilience to failures.
Thus, the use of Ethernet in a metro network allows service providers to take advantage of volumes that a much larger enterprise segment commands.
Carrier-Ethernet Transport (CET) usually involves an evolution of conventional Ethernet and comprises multiple technology components.
Connectivity-Fault Management (CFM-OAM) provides the much-required OAM that makes Ethernet carrier grade.
Such support needs to include service level agreement (SLA) management capabilities, with consistent performance over fiber, DSL, bonded PDH, and SDH/SONET access lines.
As a result, must-have Carrier Ethernet demarcation features include sophisticated traffic management and hierarchical quality of service (QoS) mechanisms, standard end-to-end operations, administration and maintenance (OAM) and performance monitoring, extensive fault management and diagnostics, and SDH/SONET-like resiliency to reduce service provider operating costs and capital expenses.
[citation needed] The key roles have been played by the Institute of Electrical and Electronics Engineers (IEEE) 802.1 and 802.3 standards committees.