Ethernet Video Series
Episode 07, Segment 01 of 10
Ethernet Delivers the Internet
Most home-office or small-office situations bring the Internet into the local network through an Ethernet connection, leading to a basic router, interfaced with a DSL modem or a cable modem.
In order to understand the way Ethernet brings us the Internet, we have to take a little diversion into the concept of messages within messages.
Let me call your attention to a common, ordinary envelope. The outside of the envelope contains destination address and source address after the usual pattern that has been established for many, many years. In this case, the envelope is addressed to the Smith family, of 140 East Lilac, in Sunol, California. And, of course, the source address is placed in the upper left-hand corner according to well-established conventions.
It turns out that when a postman delivers this envelope to the Smith family
according to this postal address, heís performing a function thatís pretty
similar to the way Ethernet delivers frames using Ethernet addresses.
Our example will get a little more interesting as we open up the envelope and see whatís inside. Of course, opening the envelope and looking inside is something that the postman will generally not do. Heís only concerned with the address on the outside of the envelope.
Episode 07, Segment 02 of 10