10-Gigabit Ethernet (10-GBE), ratified in June 2002, is a logical extension of previous Ethernet versions. 10-GBE was designed to make the transition from LANs to Wide Area Networks (WANs) and Metropolitan Area Networks (MANs). It offers a cost effective migration for high-performance and long-haul transmissions at up to 40 kilometres. Its most common application now is as a backbone for high-speed LANs, server farms and campuses. It also enables you to connect geographically separated LANs to new MANs and WANs via dark fiber, dark wavelengths or SONET/SDH networks.
10-GBE supports existing Ethernet technologies
10-GBE uses the same layers (MAC, PHY and PMD), and the same frame sizes and formats. But the IEEE 802.3ae spec defines two sets of physical interfaces: LAN (LAN PHY) and WAN (WAN PHY).
The most notable difference between 10-GBE and previous Ethernets is that 10-GBE operates in full-duplex only and specifies fibre optic media. The chart below notes the differences between Gigabit and 10-Gigabit Ethernet.
10-GBE
Distance
Wavelength
Cable
10GBASE-SR
300 m
850 nm
Multimode
10GBASE-SW
300 m
850 nm
Multimode
10GBASE-LR
10 km
1310 nm
Single-Mode
10GBASE-LW
10 km
1310 nm
Single-Mode
10GBASE-LX4
Multimode 300 m /
Single-Mode 10 km
1310 nm
WWDM
Multimode oder
Single-Mode
10GBASE-ER
40 km
1550 nm
Single-Mode
10GBASE-EW
40 km
1550 nm
Single-Mode
10GBASE-CX4*
15 m
-------
4 x Twinax
10GBASE-T*
25-100 m
-------
Twisted Pair
* Proposed for copper.
The alphabetical coding for 10-GBE is as follows:
S = 850nm
X = 8B/10B signal encoding
L = 1310 nm
R = 66B encoding
E = 1550 nm
W = WIS interface (for use with SONET).
At a glance—Gigabit vs. 10-Gigabit Ethernet
Gigabit
10-Gigabit Ethernet
- CSMA/CD full-duplex
- Full-duplex only
- Leveraged Fibre Channel PMDs
- New optical PMDs
- Reused 8B/10B coding
- New coding scheme 64B/66B
- Optical/copper media
- Optical (developing copper)
- Support LAN to 5 kilometres
- Support LAN to 40 kilometres
- Carrier extension
- Throttle MAC speed for
WAN
- Use SONET/SDH as
Layer 1 transport