ATM
Asynchronous Transfer Mode
A network technology protocol based on encoding and transmitting data in relatively small cells/packets of a fixed length. Allows for high-speed transmission of video, audio and data over the same network.
ATM is a connection-oriented switching technique with very high speed and high bandwidth. The CCITT (Consultative Committee International Telephone and Telegraph) is betting on ATM's many benefits for the future broadband network.
DWDM
Dense Wavelength Division Multiplexing
A more powerful version of WDM, allows for greater capacity to be transmitted over fiber optic cable by multiplexing as many as 8 or more wavelengths over a single fiber. This process increases the capacity of existing optical networks.
A key advantage to DWDM is that it's protocol- and bit-rate-independent. DWDM-based networks can carry different types of traffic at different speeds over an optical channel.
DSL
Digital Subscriber Loop
A technology designed to allow high-speed transmission of digital data over the copper telephone lines of the telephone network to homes and businesses. The DSL line can carry data and voice signals, providing"always-on" Internet access.
There are many types of DSL including ADSL,VDSL,SDSL etc. This family of technologies provide high speed data connectivity over the local loop or final mile.
FTTH
Fiber To The Home
An approach to the last-mile problem of giving residences high-speed broadband access to digital services and Internet access. The installation of optical fiber from a telephone switch directly into the subscriber's home. Fiber optic cable is an alternative to coaxial cable.
The technology promises speeds of up to 100M bit/sec and can bring high-speed service to homes at a greater distance from a central switch than DSL
ISDN
Integrated Serviced Digital Network
A mature switched-access service that is able to exchange digital voice, data and image information simultaneously over phone (copper) lines. The network is based upon 64Kbps circuits and makes all circuits end-to-end digital; ISDN Speeds for data transmission can reach 280 Kbps with compression. It is expected to be overtaken by faster xDSL technologies.
IP
Internet Protocol
IP specifies the format of packets, also called datagrams, and the addressing scheme. Most networks combine IP with a higher-level protocol called Transmission Control Protocol (TCP), which establishes a virtual connection between a destination and a source.
ONT
Optical Network Terminal
The three main elements in the PON (Passive Optical Networking) networks are the Optical Line Terminal (OLT), the Passive Optical Splitters, and the Optical Network Terminal (ONT). The OLT at the central office connects the subscriber's local loop to the network. A Splitter divides the single line into 32 equal channels. The ONT (or ONU in businesses) provides the interface between the optical network and the home/business.
PON
Passive Optical Network
A passive optical network (PON) is a point-to-multipoint, fiber to the premises network architecture in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises, typically 32-128. A PON consists of an Optical Line Terminal (OLT) at the service provider's central office and a number of Optical Network Units (ONUs) near end users. A PON configuration reduces the amount of fiber and central office equipment required compared with point to point architectures.
Downstream signals are broadcast to each premises sharing a fiber. Encryption is used to prevent eavesdropping.
Upstream signals are combined using a multiple access protocol, invariably time division multiple access (TDMA). The OLTs "range" the ONUs in order to provide time slot assignments for upstream communication.
SONET
Synchronous Optical Network
Having a similar architecture to SDH, SONET is created to provide the flexibility needed to transport many digital signals with different capacities. It uses a self-healing ring architecture to complete the rerouting and time division multiplexing (TDM) to send multiple data streams.
SDH
Synchronous Digital Hierarchy
The international standard set by the ITU for fiber optic data transmissions. The technique is used to carry high capacity information over long distances. The North American equivalent of SDH is SONET.
VLAN
Virtual Local Area Network
A network of computers that behave as if they are connected to the same wire even though they may actually be physically located on different segments of a LAN. VLANs are configured through software rather than hardware, which makes them extremely flexible. One of the biggest advantages of VLANs is that when a computer is physically moved to another location, it can stay on the same VLAN without any hardware reconfiguration.
VoIP
Voice over Internet Protocol
VoIP is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls by sending voice data in packets using IP rather than by traditional circuit transmissions of the PSTN. One advantage of VoIP is avoiding the tolls charged for ordinary telephone service. Another cost saving is that VoIP leverages existing IP infrastructure and reduces the need for traditional telephony equipment (PABX, TDM phones, etc.)
