Specifications

Engineering Guidelines
354
ICP – IP Communications Platform. Includes gateway function, call control, plus a number
of other features, such as voice mail.
IP Address – Internet protocol address. A 32-bit address assigned to hosts using TCP/IP.
An IP address belongs to one of five classes (A, B, C, D, or E) and is written as 4 octets
separated by periods (dotted decimal format). Each address consists of a network number, an
optional subnetwork number, and a host number. The network and subnetwork numbers
together are used for routing, while the host number is used to address an individual host within
the network or subnetwork.
IP – Internet Protocol. An encapsulation protocol that allows data to be passed from one end
user to another. Typically this was over the Internet, but the same protocol is now used within
businesses.
IrDA – Infrared Data Association. The IrDA is an industry-sponsored organization set up in
1993 to create international standards for the hardware and software used in infrared
communication links. Infrared radiation (IR) is the same technology used to control a TV set
with a remote control.
IRDP – ICMP Router Discovery Protocol. An extension to the ICMP protocol that provides a
method for hosts to discover routers and a method for routers to advertise their existence to
hosts.
ISDN – Integrated Services Digital Network. The digital PSTN network. Integrated because
this network carries both voice and data and provides direct digital connectivity to the user via
BRI or PRI connections.
ISL – Inter-Switch Link. Cisco-proprietary protocol that maintains VLAN information as traffic
flows between switches and routers.
L2 – Layer 2. The second layer of encapsulation of data to be transferred. Typically with TCP/IP
this includes the MAC layer.
L3 – Layer 3. The third layer of encapsulation of data to be transferred. Typically with TCP/IP
this includes the IP address.
LAN – Local Area Network. This is a network within a local area, typically within a radius of
100 m. The transmission protocol is typically Ethernet II.
Leased IP – An IP address that has been assigned through DHCP and is valid only for the
duration of the agreed lease time.
LLDP – Link Layer Discovery Protocol. A low level protocol used to pass information about
the connection configuration between two end devices, for example VLAN. Typically this would
be between an end device such as a PC or IP phone and the network access port on the Layer
2 switch.
LLDP-MED – Link Layer Discovery Protocol - Media End-point Discovery. LLDP-MED is
an extension of LLDP that provides auto-configuration and exchange of media-related