Metro Ethernet (MetroE)

Metro Ethernet (MetroE) as the name suggests uses Ethernet links to connect customer network to a service Provider’s device. The customers of Metro Ethernet is usually Enterprises that need to connect their several offices. Metro Ethernet service uses layer 2 standards i.e, it forwards ethernet frames from one customer device to another.

Metro Ethernet is analogous to a large LAN that forwards frames between different VLANs. As the area of service covered by Metro Ethernet is large, Service Providers need to implement Fiber Ethernet standard. Fiber Ethernet supports high speed and long-distance cabling without loss.

Figure – Metro Ethernet Analogy

Metro Ethernet Implementation :
If we think from customer’s (Enterprise) point of view, each site must be connected to Service Provider’s network. Also, there is no need to connect two enterprise sites directly because that is reason why enterprises are using Metro Ethernet. It is not feasible for any enterprise to lay down Ethernet cables across cities just to connect their different sites.

From Service Provider’s perspective, it needs to place a switch at a place where switch is accessible to a large number of customers. This place is called a Point of Presence (PoP). PoP is chosen by thought in mind that customer’s ethernet standard is able to withstand that distance. The connection between customer and service provider’s device is called user network interface (UNI). User means customer and network refer to Service Provider’s network.

Figure –Metro Ethernet Implementation

For Ethernet standards to be used for Metro Ethernet, IEEE suggest some standards as tabulated below –

Standard Name	Speed	Distance
100Base-LX10	100 Mbps	10 Km
1000Base-LX	1 Gbps	5 Km
1000Base-LX10	1 Gbps	10 Km
1000Base-ZX	1 Gbps	100 Km
10GBase-LR	10 Gbps	10 Km
10GBase-ER	10 Gbps	40 Km