|  | 6.3 | LMI Features
| 6.3.1 | Global addressing
In addition to the common LMI features, several optional LMI extensions are extremely useful in an internetworking environment. The first important optional LMI extension is global addressing. With this extension, the values inserted in the DLCI field of a frame are globally significant addresses of individual end-user devices (for example, routers). As noted earlier, the basic (nonextended) Frame Relay specification supports only values of the DLCI field that identify PVCs with local significance. In this case, there are no addresses that identify network interfaces, or nodes attached to these interfaces. Because these addresses do not exist, they cannot be discovered by traditional address resolution and discovery techniques. This means that with normal Frame Relay addressing, static maps must be created to tell routers which DLCIs to use to find a remote device and its associated internetwork address. In the Figure, note that each interface has its own identifier. Suppose that Pittsburgh must send a frame to San Jose. The identifier for San Jose is 22, so Pittsburgh places the value 22 in the DLCI field and sends the frame into the Frame Relay network. Each router interface has a distinct value as its node identifier, so individual devices can be distinguished. This permits routing in complex environments. Global addressing provides significant benefits in a large, complex network. The Frame Relay network now appears to the routers on its periphery like any LAN.