The term 802.3 is an IEEE standard or specification for Ethernet, a method of physical communication in a local area network or LAN. The Institute of Electrical and Electronics Engineers or IEEE is the governing body which maintains the standards. In general the 802.3 specifies the physical media and the working standards of Ethernet.
802.3 Ethernet Specification
- Media Types and Connectors
- Layer 2 Framing
- Speeds and Duplex
- Distances or Lengths
Take for example an Ethernet segment between a Customer Router and lets say AT&T. Due to the great distance between Customer locations and the AT&T CO or POP there would a couple of IEEE 802.3 standards that would come into play in order to provide connectivity.
With demand for more and more bandwidth, and the advent of long reaching optical Carrier networks Ethernet is not longer really considered just a Layer 1, 2 LAN protocol. The IEEE is also responsible for such Layer 2 Protocols as 802.1q, 802.1d, 802.1w and more.
IEEE Links
Some of the more common IEEE 802.3x standards
- Standard: 10BASE-2
- Layer 1: Coaxial
- Distance: 607 feet or 185 meters
- Speed: 1 Meg
IEEE 802.3i
- Standard: 10BASE-T
- Layer 1: CAT5
- Distance: 328 feet or 100 meters
- Speed: 1 Gigabit
IEEE 802.3z
- Standard: 1000BASE-CX
- Layer 1: CAT5e
- Distance: 82 feet or 25 meters
- Speed: 1 Gigabit
IEEE 802.3z
- Standard: 1000BASE-TX
- Layer 1: CAT6
- Distance: 82 feet or 25 meters
- Speed: 1 Gigabit
IEEE 802.3z
- Standard: 1000BASE-SX
- Layer 1: Optical
- Distance: 1804 feet or 550 meters
- Speed: 1 Gigabit
IEEE 802.3ae
- Standard: 1000BASE-SR
- Layer 1: Optical
- Distance: 2788 feet or 850 meters
- Speed: 10 Gigabit
Single Mode vs Multimode
With Multimode fiber optic cables the diameter of the core is much larger then single mode witch allows the light to propagate. Because of this, the number of light reflections created as the light passes through the core increases, creating the ability for more data to pass through at a given time. Because of the high dispersion and low attenuation rate with this type of fiber, the quality of the signal is reduced over long distances. This application is typically used for short distance in Local Area Networks or LANs.
With single mode fiber optic cables the diameter of the core is much smaller which allows only a single mode of light to pass through the core. Because of this, the number of light reflections created as the light passes through the core decreases, lowering attenuation and creating the ability for the signal to travel faster, further. This application is typically used in long distance, higher bandwidth runs by Telcos, CATV companies, and Colleges and Universities.
Multimode
- Glass fiber
- Simplex or Duplex
- SC, LC, FC or ST
- 50 to 62.5 micron core
- Lower bandwidth / Higher attenuation
- Wavelength 850 nm – Connector ST 3 km or 2 miles
- Wavelength 1310 nm – Connector ST 10 km or 6 miles
Single Mode
- Glass fiber
- Simplex or Duplex
- SC, LC, FC or ST
- 9 um core
- Higher Bandwidth / Lower attenuation
- Wavelength 1310 nm – Connector ST 3 km or 2 miles
- Wavelength 1310 nm – Connector FC 30 km or 20 miles
- Wavelength 1550 nm – Connector FC 60 km or 40 miles
I hope you found this post on the Wire helpful and informative. Be sure to let me know what you think by leaving suggestions, and feedback in the comments section below. You can find out more about these and other articles be checking out recent posts and archives. To learn more about me be sure to check out the About page. And as always thanks again for visiting The Packet.
