Networking at Layer 2: Benefits of Ethernet Frames

• 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.

Note: Networking at the frame level says nothing about the presence or absence of IP addresses at the packet level. Almost all ports, links, and devices on a network of LAN switches still have IP addresses, just as do all the source and destination hosts. There are many reasons for the continued need for IP, not the least of which is the need to manage the network. A device or link without an IP address is usually invisible to most management applications. Also, utilities such as remote access for diagnostics, file transfer of configurations and software, and so on cannot run without IP addresses as well as MAC addresses.