Gigabit Ethernet Protocol Standards Overview
To attach Layer 2 service policies, such as QoS, to the Ethernet interface, refer to the appropriate Cisco IOS
XR software configuration guide.
Gigabit Ethernet Protocol Standards Overview
The Gigabit Ethernet interfaces support the following protocol standards:
These standards are further described in the sections that follow.
IEEE 802.3 Physical Ethernet Infrastructure
The IEEE 802.3 protocol standards define the physical layer and MAC sublayer of the data link layer of wired
Ethernet. IEEE 802.3 uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access at a
variety of speeds over a variety of physical media. The IEEE 802.3 standard covers 10 Mbps Ethernet.
Extensions to the IEEE 802.3 standard specify implementations for 10-Gigabit Ethernet, and Fast Ethernet.
IEEE 802.3ab 1000BASE-T Gigabit Ethernet
The IEEE 802.3ab protocol standards, or Gigabit Ethernet over copper (also known as 1000BaseT) is an
extension of the existing Fast Ethernet standard. It specifies Gigabit Ethernet operation over the Category
5e/6 cabling systems already installed, making it a highly cost-effective solution. As a result, most copper-based
environments that run Fast Ethernet can also run Gigabit Ethernet over the existing network infrastructure to
dramatically boost network performance for demanding applications.
IEEE 802.3z 1000 Mbps Gigabit Ethernet
Gigabit Ethernet builds on top of the Ethernet protocol, but increases speed tenfold over Fast Ethernet to 1000
Mbps, or 1 Gbps. Gigabit Ethernet allows Ethernet to scale from 10 or 100 Mbps at the desktop to 100 Mbps
up to 1000 Mbps in the data center. Gigabit Ethernet conforms to the IEEE 802.3z protocol standard.
By leveraging the current Ethernet standard and the installed base of Ethernet and Fast Ethernet switches and
routers, network managers do not need to retrain and relearn a new technology in order to provide support
for Gigabit Ethernet.
IEEE 802.3ae 10 Gbps Ethernet
Under the International Standards Organization's Open Systems Interconnection (OSI) model, Ethernet is
fundamentally a Layer 2 protocol. 10-Gigabit Ethernet uses the IEEE 802.3 Ethernet MAC protocol, the IEEE
802.3 Ethernet frame format, and the minimum and maximum IEEE 802.3 frame size. 10 Gbps Ethernet
conforms to the IEEE 802.3ae protocol standards.
Just as 1000BASE-X and 1000BASE-T (Gigabit Ethernet) remained true to the Ethernet model, 10-Gigabit
Ethernet continues the natural evolution of Ethernet in speed and distance. Because it is a full-duplex only
and fiber-only technology, it does not need the carrier-sensing multiple-access with the CSMA/CD protocol
that defines slower, half-duplex Ethernet technologies. In every other respect, 10-Gigabit Ethernet remains
true to the original Ethernet model.
IEEE 802.3ba 100 Gbps Ethernet
IEEE 802.3ba is supported on the Cisco 1-Port 100-Gigabit Ethernet PLIM.
Interface and Hardware Component Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
26
Configuring Ethernet Interfaces