In spite of the difficulties of using a bridge to perform the network role of a router, many
vendors, customers, and service providers are attracted to the idea of using Ethernet in
as many places of their networks as possible.

The perceived benefits of Ethernet are:

•

Most information starts and ends inside Ethernet frames. Today, this applies to data,
as well as voice (for example, VoIP) and video (for example, Web cams).

•

Ethernet frames have all the essentials for networking, such as globally unique source
and destination addresses, error control, and so on.

•

Ethernet frames can carry any kind of packet. Networking at Layer 2 is protocol
independent (independent of the Layer 3 protocol). Layer 2 networks work for IP
packets and all other Layer 3 protocols.

•

More layers added to the Ethernet frame only slow the networking process down
(“nodal processing delay”).

•

Adjunct networking features such as class of service (CoS) or multicasting can be
added to Ethernet as readily as IP networks.

If more of the end-to-end transfer of information from a source to a destination can be
done in the form of Ethernet frames, more of the benefits of Ethernet can be realized on
the network. Networking at Layer 2 can be a powerful adjunct to IP networking, but it is
not usually a substitute for IP networking.

Chapter 1: Overview of Ethernet Solutions