Ethernet virtual connection
When a telecommunications service provider (e.g., MSO, CLEC, ILEC, IXC) offers a Metro Ethernet service that is compliant with the Metro Ethernet Forum (MEF) specifications, the service has two basic elements: the UNI by which the service is provided to the customer, and an EVC that establishes a communication relationship between one or more UNIs.
In Metro Ethernet services, there are three types of EVC:
- Point-to-point: an EVC that supports communication between two (and only two) UNIs. This type of EVC operates similarly to a virtual circuit. It is an essential component of a service type known as E-line
- Multipoint-to-multipoint: an EVC that supports any-to-any communication between two or more UNIs. This EVC creates a service that behaves like a switched Ethernet environment. It is an essential component of a service type known as E-LAN.
- Point-to-multipoint: an EVC that supports communication between two or more UNIs, but does not support any-to-any communication. Specifically, UNIs are designated as root or leaf. Transmissions from the root are delivered to the leaves, and transmission from the leaves are delivered to the root(s). No communication can occur between the leaves or between the roots. This EVC can be used in environments that want/need a hub-and-spoke communication arrangement without needing to configure multiple point-to-point EVCs. It is an essential component of a service type known as E-Tree
|<mp3>http://podcast.hill-vt.com/podsnacks/2007q4/evc.mp3%7Cdownload</mp3> | Ethernet virtual connection (EVC)|