HP-UX VLAN Administrator's Guide, February 2007

Glossary
This glossary provides definitions for common terms relevant to HP-UX VLANs.
1000Base-SX A Gigabit Ethernet (1000-Mb/s) communication method for Ethernet LANs designed to operate
over two multimode fiber cables, as specified in IEEE 802.3z/D.50-1988.
1000Base-T A Gigabit Ethernet (1000-Mb/s) communication method for Ethernet LANs designed to operate
over Category 5, 5e, or 6 unshielded twisted pair (UTP) cabling, as specified in the IEEE 802.3ab
standards.
100Base-T A 100 Mbit/s communication method for LANs specified in the IEEE 802.3u-1995 standard. The
official name for Fast Ethernet.
802.1p IEEE standard supplement, now incorporated in IEEE 802.1p. Defines eight priority levels for
traffic classification at the data link level and suggests how they might be used.
See also priority.
802.1Q IEEE Standard that specifies the architecture for VLAN tagging, association, and VLAN-capable
bridges.
alias Name of the interface that corresponds to a given Internet address on a system.
APA Auto Port Aggregation. The HP software product that creates link aggregates, which provide
a logical grouping of two or more physical ports into one trunk. APA also provides load
balancing and automatic link failover detection and recovery.
ATM Asynchronous transfer mode. A form of digital transmission based on the transfer of units of
information known as cells. It is suitable for the transmission of image, voice, video, and data.
autonomous
system
A group of IP networks and routers, typically administered by a single entity, such as an Internet
Service Provider, that adheres to a common routing policy. Networks and routers are logically
grouped into autonomous systems for routing purposes, particularly for the Border Gateway
Protocol (BGP). The BGP is used by routers in the Internet to determine how to route packets
to autonomous systems. Within autonomous systems, routers use an Interior Gateway Protocol
to route packets to individual IP nodes.
BGP Border Gateway Protocol. An exterior gateway protocol used to select routes between
autonomous systems.
bridge A device that forwards link-layer packets based on the destination Media access control (MAC)
address, such as an Ethernet address. A bridge connects LANs or LAN segments and is an OSI
Layer 2 device.
broadcast 1. A network transmission method in which data is sent to all nodes on the network. 2. The
transmission of packets to a link-layer broadcast address so that all nodes in a physical network
segment receive and process the packets. 3. The transmission of IP packets to a network or
subnet broadcast IP address so that all nodes in an IP network or subnet receive and process
the packets.
card instance
number
A number that uniquely identifies a device within a device class. For network interface cards,
the card instance number is the same as the PPA.
See also device class, PPA.
CIDR Classless interdomain routing. A method for specifying the network prefix length of an IPv4
address, where the address is followed by a slash (/) and the prefix length. The network prefix
length specifies the number of bits in the address that represent the network or subnet portion
of the address; the remaining bits in the address are the host portion of the address.
CoS Class of Service. The ability to provide different levels of service to various traffic flows. A flow
can be determined explicitly via tags or implicitly from the frame contents (such as the IP
address or ToS field). CoS network management is when similar types of traffic (for example,
voice, video, or data) are grouped together and assigned a priority. Unlike Quality of Service
(QoS) traffic management, CoS does not guarantee a level of service in terms of bandwidth and
delivery time.
destination
address
A field in the message packet format identifying the end nodes to which the packet is being
sent.
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