816 Appendix F:Glossary
NN47250-500 (Version 03.01)
IGMP snooping A feature that prevents the flow of multicast stream packets within a virtual LAN
(VLAN) and forwards the multicast traffic through a path to only the clients that want to receive it. A
WLAN—Security Switch (WSS) uses IGMP snooping to monitor the Internet Group Management Protocol
(IGMP) conversation between hosts and routers. When the WSS detects an IGMP report from a host for a
given multicast group, it adds the host’s port number to the list for that group. When it detects an IGMP host
leaving a group, the WSS removes the port number from the group list.
Industry Canada See IC.
information element See WPA IE.
infrastructure network One of two IEEE 802.11 network frameworks. In an infrastructure network,
all communications are relayed through an AP. Wireless devices can communicate with each other or with a
wired network. The network is defined by the distance of mobile stations from the access point, but no
restriction is placed on the distance between stations. Stations must request association with the access point to
obtain network services, which the access point can grant or deny based on the contents of the association
request. Like most corporate wireless LANs (WLANs), which must access a wired LAN for file servers and
printers, a Nortel WLAN 2300 system is an infrastructure network. Compare ad hoc network.
initialization vector (IV) In encryption, random data used to make a message unique.
Institute of Electrical and Electronic Engineers See IEEE.
integrity check value See ICV.
interface A place at which independent systems meet and act on or communicate with each other, or the
means by which the interaction or communication is accomplished.
International Organization for Standardization See ISO.
Internet Authentication Service See IAS.
Internet Group Management Protocol See IGMP.
Interswitch Link See ISL.
ISL Interswitch Link. A proprietary Cisco protocol for interconnecting multiple switches and maintaining
virtual LAN (VLAN) information as traffic travels between switches. Working in a way similar to VLAN
trunking, described in the IEEE 802.1Q standard, ISL provides VLAN capabilities while maintaining full
wire-speed performance on Ethernet links in full-duplex or half-duplex mode. ISL operates in a point-to-point
environment and supports up to 1000 VLANs.
ISO International Organization for Standardization. An international organization of national standards
bodies from many countries. ISO has defined a number of computer standards, including the Open Systems
Interconnection (OSI) standardized architecture for network design.
IV See initialization vector (IV).
jumbo frame In an Ethernet network, a frame whose data field exceeds 1500 bytes.
LAWN See WLAN.