Sunrise telecom XTT 5000, Руководство пользователя, Страница: 161 / 181

Technology Overview
Technology: Ethernet MAC Addresses Home
The MAC addresses is six bytes, written in hexadecimal.
• The first three bytes contain a vendor code, also known as the OUI
(Organizationally Unique Identifier) or company_id.
• The last three bytes contain a unique station ID. Vendor codes are assigned
and administered by the IEEE.
The OUI for Sunrise Telecom is 00-D0-DD. The station IDs are assigned by the
manufacturers are often tied to the serial number of the device.
Vendor codes: http://standards.ieee.org/regauth/oui/oui.txt
MAC Address Format
Unicast : Most Ethernet traffic is designated to travel from one station to another
specific station. This is called unicast traffic.
Broadcast Ethernet traffic is sent to all stations on the network; such frames are
given a MAC destination of all-ones: FF-FF-FF-FF-FF-FF. Because broadcast traffic is
very polluting, it should be avoided whenever possible.
Multicast traffic is sent from one station, but is then directed to a group of stations.
Multicasting is more efficient and more network-friendly than broadcasting. Typical
applications for multicast traffic include IP video delivery and LAN protocols.
Multicast traffic is designated by setting the first bit of the address to 1. Because the
least significant bit is transmitted first, this means the last bit of the first byte is set
to 1; in other words, the byte value is odd. The MAC vendor code used for IP
multicast packets it typically 01-00-5E-xx-xx-xx, as specified by RFC 1112.
Unicast/Multicast Testing Note
IPG
Frame Size Efficiency
VLAN Tagging
MPLS
Where do you want to go next?
Ethernet Frames
Ethernet Overview
Home
155