Physical Layers for Ethernet
In this lesson, we'll look at various types of physical layers and their limitations and benefits to Ethernet.
Several physical layers have been defined for Ethernet networks.
10Base5
The first type of physical layer, usually called 10Base5, provided Mbps over a thick coaxial cable. The characteristics of the cable and transceivers that were used then enabled the utilization of 500 meter long segments. A 10Base5 network can also include repeaters between segments.
10Base2
The second type of physical layer was 10Base2. 10Base2 used a thin coaxial cable that was easier to install than the 10Base5 cable but could not be longer than 185 meters.
10BaseF
A 10BaseF type of physical layer was also defined to transport Ethernet over point-to-point optical links.
10BaseT
Twisted Pairs
The major change to the physical layer was the support of twisted pairs in the 10BaseT specification. Twisted pair cables are traditionally used to support the telephone service in office buildings. Most office buildings today are equipped with structured cabling. Several twisted pair cables are installed between any room and a central telecom closet per building or per floor in large buildings. These telecom ...