What is Metro Ethernet?

We’re all familiar with Ethernet, the packet switched network standard that runs on our LANs. But what is Metro Ethernet and how does it differ from Carrier Ethernet? Is Metro Ethernet the same protocol running on local networks but just going longer distances?

From a users standpoint, Metro Ethernet really is just like local Ethernet. In fact, the connection to the Metro Ethernet Network is a standard Ethernet connector. There are no special interface modules needed to convert protocols or establish signal levels. You simply plug one network into the local Metro Ethernet connection and another network into the Metro Ethernet connection across town and they are connected together.

Actually, it has taken quite a bit of effort to make Metro Ethernet so simple. That work has been done by the Metro Ethernet Forum (MEF), a industry standards group. The beauty of standards is that both providers and users know exactly what they are dealing with. There aren’t the ugly surprises that come from trying to engineer basically incompatible products and services.

The terms Metro Ethernet and Carrier Ethernet tend to be used interchangeably. Carrier Ethernet is meant to describe standard switched Ethernet adapted for use over much longer spans than within a building or corporate campus. Carrier Ethernet can be deployed on IP core networks, over SONET/SDH, or over MPLS networks. The end user isn’t generally aware of the transport mechanism. From the customer’s standpoint, it’s just Ethernet ports at each location.

Metro Ethernet is the term that is used to refer to Ethernet services limited to a particular city or metropolitan area of city and suburbs. It’s a popular service for companies that have two or more separate business locations locally. Medical groups consisting of several hospitals, diagnostic centers and clinics are also find Metro Ethernet attractive because of its high bandwidths, ease of connection and lower costs compared to traditional telecom line services.

The customer service connection is made at a User-Network Interface (UNI) installed by the service provider. On one side is the Customer Equipment (CE) and on the other side is the Metro Ethernet Network (MEN). The path between UNIs is made through an Ethernet Virtual Connection (EVC). The EVC maintains the Ethernet MAC address and frame contents unaltered, so it is possible to establish Layer 2 connectivity between locations. It also ensures that traffic goes between the proper UNIs and nowhere else. Think of an EVC as similar in function to a “wired” network connection between two locations.

There are two Metro Ethernet services you’ll be interested in. One is Ethernet Line or E-Line service. This is the equivalent of point to point private line service using T1 or DS3. The other is Ethernet LAN or E-LAN service. This is a multipoint to multipoint service that can be used in place of private proprietary networks, Frame Relay, or MPLS networks to connect multiple locations in a mesh network. Both of these services are suitable for linking offices, factories, warehouses, data centers and other sites within a metropolitan area.

Could your organization benefit from Metro Ethernet? If you have need to connect two or more locations within a city or small geographical area, you may be able to get more bandwidth for less money than you can with other connectivity solutions. To find out, check Metro Ethernet Network availability and pricing for your business locations.