Ethernet Families
The Ethernet physical layer has evolved over time to utilize several media interfaces and transmission speeds, for example:
Physical Media
- Co-axial
- Twisted Pair
- Fiber-Optic
Speeds
- 1 Mbps
- 10 Mbps
- 100 Mbps
- 1000 Mbps
- 10 Gbps
- 100 Gbps
Ethernet Family Naming Scheme
Ethernet families are named according to certain medium specifications:
For example, Fast Ethernet is named:
Bit Rate
The nominal usable speed for the MAC layer.
Examples:
- 10, 100, 1000 (no suffix = megabits/second)
- 10G (G suffix = gigabits/second)
Signaling Type
Medium
- T = twisted pair
- C = copper/twinax
- F = fiber (various wavelengths)
- S = 850 nm short wavelength (multi-mode-fiber)
- L = 1300 nm long wavelength (mostly single-mode-fiber)
PCS Encoding
Certain bit encoding schemes are employed at certain speeds to reduce the required transmission bandwidth.
- X = 8b/10b block encoding (Gigabit ethernet) or 4b/5b (Fast ethernet)
- R = 64b/66b for large blocks (10G ethernet)
#Lanes
Refers to the number of signal-carrying wires (or wire-pairs) used per link (1, 2, 4, 10).
Common Families Supported by Microchip's Ethernet Portfolio
Family Type | Medium | Data Rate | Segment Length |
---|---|---|---|
10BASE-T | UTP* | 10 Mbps | 100 m |
100BASE-TX | 2-Pair CAT5 UTP | 100 Mbps | 100 m |
100BASE-FX | 2 Optical Fibers | 100 Mbps | 100 m |
1000BASE-T | 4-Pair CAT5 UTP | 1000 Mbps | 100 m |
UTP - Unshielded twisted pair