Gigabit Ethernet Protocol Standards Overview - Cisco ASR 9000 Series Configuration Manuallines

Gigabit Ethernet Protocol Standards Overview

• AC-to-PW—Traffic reaching the PE is tunneled over a PW (pseudowire) (and conversely, traffic arriving
• Local switching—Traffic arriving on one AC is immediately sent out of another AC without passing
• PW stitching—Traffic arriving on a PW is not sent to an AC, but is sent back into the core over another
Keep these in mind when configuring L2VPN on an Ethernet interface:
• L2VPN links support QoS (Quality of Service) and MTU (Maximum Transmission Unit) configuration.
• If your network requires that packets are transported transparently, you may need to modify the packet's
Use the show interfaces command to display AC and pseudowire information.
Gigabit Ethernet Protocol Standards Overview
The Gigabit Ethernet interfaces support these protocol standards:
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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 Gigabit Ethernet, 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.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
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over the PW is sent out over the AC). This is the most common scenario.
through a pseudowire.
PW.
destination MAC (Media Access Control) address at the edge of the Service Provider (SP) network. This
prevents the packet from being consumed by the devices in the SP network.
IEEE 802.3 Physical Ethernet Infrastructure
IEEE 802.3ab 1000BASE-T Gigabit Ethernet
IEEE 802.3z 1000 Mbps Gigabit Ethernet
IEEE 802.3ae 10 Gbps Ethernet
The Carrier Ethernet Model