?– Physical layer This comprises the infrastructure that enables the physical
transmission of data, and includes wired (coax, copper, fiber) and wireless
media.
?– Transport/Network4 layer This layer provides the transport of Ethernet services
(in terms of Ethernet frames) and employs a variety of different technologies
operating over the Physical layer.
?– Ethernet layer This layer enables the instantiation of the Ethernet connectivity
services, whether E-LINE or E-LAN (as defined in Chapter 2). This layer is
responsible for all the service-aware aspects of the Ethernet flow, including the
Operations, Administration, and Maintenance and Provisioning (OAMP)necessary
to support these connectivity services.
?– Applications layer This layer supports the applications carried over the
Ethernet services provided at the Ethernet layer. The Ethernet layer can also be
used as a transport layer for some of the application layer connectivity services,
such as T1, ATM, and so on.
4 We??™ve combined network and transport into one layer to highlight that the solutions will provide
transport and may also provide higher-order functions, such as switching and routing.
Pages:
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337