sonetlynx glossary

7/24/2019 SonetLynx Glossary

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GLOSSARY


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AAdd/drop

multiplexer

A network element that can add and remove information from the

network data stream. SONETLYNX is an example of a fiber optic

add/drop multiplexer.

Alarms Alarms relay information about changes in the status of the network

or network device. SONETLYNX equipment provides configurable

alarms for a variety of situations.

AMI Alternate Mark Inversion. A T1 line coding format. SONETLYNX

supports AMI and B8ZS line coding.

Asynchronous A method of data transmission that does not require a central timing

source. Asynchronous transmission uses methods such as start bits

and stop bits to identify different data characters for the receiver.

ATM Asynchronous Transfer Mode. A data transmission protocol that

uses short, fixed-length cells to transport various types of data

traffic. ATM was designed to run over a SONET fiber optic

backbone.

Attenuator An optic element that reduces the intensity of light passing through

it.

Auto ringdown

circuit

A circuit that connects two phones directly. When one phone is

lifted, the distant phone will ring.

B

B8ZS Bipolar Zero Eight Substitution. A T1 line coding format.SONETLYNX supports AMI and B8ZS line coding.

Backbone The fiber optic cable between the nodes of a network.

Backplane The part of the SONETLYNX shelf that transfers data between the

protocol modules and the OC controllers and between modules and

their associated paddleboards.


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Bandwidth The capacity of a network or device to carry data. For example the

maximum bandwidth that can be handled by an OC-1 network is51.84 Mbps.

Baud The baud rate is the rate at which data is transferred and roughly

translates to the number of bits per second.

Bit A binary digit which can be represented in voltage by an on or high

state (equaling 1) and a off or low state (equaling 0). A bit is themost basic way to store or transmit information.

BIT Built in Test

Bridge A data communication device used to connect two or more

networks. Typically a bridge is used in Ethernet and other

LAN/WAN applications. SONETLYNX reduces the need for

bridges in LAN/WAN networks.

Byte In a computer, a collection of bits that are processed together as a

single unit or data character. A byte will typically represent an

alphanumeric character, but it can also be part of a larger binary

number. The most common byte is 8 bits long (also referred to as

an octet).

Byte-

synchronous

mapping

A method of mapping payload into virtual tributaries so that sub-

rate channels can be accessed within the signal. For example, the

SONETLYNX byte-synchronous T1 module can add/drop individual

DS0s out of the T1 channel.

C

CCITT Consultative Committee on International Telegraphy and

Telephony. Part of the International Telecommunications Union

(ITU), CCITT establishes telecommunications industry standards.

Chassis The physical housing into which the SONETLYNX modules are

installed. Intelect offers a 19 chassis that holds up to 14 modules

and a 23 chassis that holds up to 17 modules. Also referred to as a

shelf. Compare with node.


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Chat A SONETLYNX NMS feature that allows system administrators at

different locations on the SONETLYNX network to exchange textmessages.

Cladding The layer of glass or other transparent material surrounding the

light-carrying core of an optical fiber.

Clear channel A digital circuit that transmits data without the need for control bits

(i.e., signaling), allowing for full bandwidth usage. In clear-channeltransport, the data is passed through network elements without any

modification.

Clocking A signal used to synchronize data transmission in synchronous

networks. The SONETLYNX network uses one timing source to

provide timing to all of the nodes.

Collision A collision occurs when two data packets attempt to use the samecable or connection at the exact same timethey "bump into" each

other. When collisions occur, both packet are ruined and will have

to be retransmitted.

Competitive

access provider

(CAP)

A company that operates a private network and provides services to

customers.

Concatenated

payloads

A method of combining several STS-1s to create a single high-

bandwidth transmission channel.

Configuration

matrix

A table containing configuration information for all SONETLYNX

nodes on a network. The development and use of this matrix is

suggested in order to facilitate the installation and use of a

SONETLYNX system.

Core The central part of an optical fiber that carries light.

Craft interface An RS-232 connection on the face of the SONETLYNX OC-1/OC-3

controller that allows connection to the SONETLYNX network.

Network parameters and module configurations can be changed by

connecting a computer with NMS software to the craft interface.


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Earth ground The connection of an electrical system to earth to provide lightning

and static protection as well as to establish the zero-voltagereference for the system.

Electromagnetic

interference

(EMI)

Noise generated when stray electromagnetic fields induce currents

in electrical conductors.

Ethernet A Local Area Network (LAN) protocol used to connect computers,

printers, workstations and other network devices. Ethernet can

accommodate up to 14,800 64 byte packets per second (10 Mbps).

Ethernet hub A piece of equipment used in an Ethernet LAN that distributes data

to Ethernet ports. The distinguishing characteristic of the Ethernet

hub is that all of the data received by the hub is broadcast to every

Ethernet port to which the hub is attached.

Encapsulated

packets

In layered network protocols, the process by which each layer adds

overhead information to the packet received from the layer before

it. For example, Ethernet networks take data packets from a PC and

adds Ethernet overhead information to the beginning and end of the

packet. In turn, when the Ethernet packet is prepared for

transmission over a SONET network, the Ethernet packet is

enclosed (encapsulated) in SONET overhead information.

Error counters A SONETLYNX Ethernet performance monitoring device used to

track the number of Ethernet errors occurring within specified time

periods. The counting periods can be defined and manipulated in

the SONETLYNX NMS.

External alarms Alarms pertaining to equipment that is not part of the SONETLYNX

network. Typically external alarms are trip relay systems.

External alarms can be routed through the SONETLYNX network by

connecting them to the OC-1/OC-3 controller or to the universal

module. Each OC-1/OC-3 controller can support up to four

external alarm inputs; each universal module can support up to

eight.


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External

equipment

End user equipment attached to the SONETLYNX modules.

Typically this includes telephones, computers, cameras, etc.

F

Fiber An extremely thin glass filament upon which light signals are

transmitted. A typical fiber is about the same diameter as a human

hair. A variety of fiber types are available to serve many customer

applications.

Fiber optics A method of transferring data from one point to another using light.

FPGA (Field Programmable Gate Array) A specialized microprocessor

that has no physical connections between its logic gates when it

leaves the factory. But it has a huge number of potential

connections, that can be firmed up in the field by a programmerwith the right tools. The XILINX processor on each SonetLYNX

module is an example of a FPGA.

Frequency

division

multiplexing

Combining analog signals by assigning each a different carrier

frequency and merging them in a single signal with a broad array of

frequencies.

FXO Foreign Exchange Office.

FXS Foreign Exchange Station.

G

Grooming The process of allocating the least amount of bandwidth possible

for each communication channel. For example, the SONETLYNX

low-speed data module can be provisioned so that each channel uses

only one DS0.

Grounding The process of attaching electrical equipment to a ground.

SONETLYNX equipment must be attached to earth ground to

prevent damage from electrical surges.


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HHP A network management software program used to operate the

SONETLYNX network. The provisioning and alarm tracking

functions operate through HP

OPENVIEW

OPENVIEW

Hub

.

A piece of equipment used in an Ethernet LAN that distributes data

to Ethernet ports. The distinguishing characteristic of the Ethernet

hub is that all of the data received by the hub is broadcast to everyEthernet port to which the hub is attached.

I

Interoperability The ability for systems from different vendors to communicate with

each other. SONETLYNX has the ability to interoperate with several

other vendors SONET equipment.

ITU International Telecommunications Union. See CCITT

J

Jabbering In LAN technology, this term refers to continuously sending

random data (garbage). Normally used to describe the action of a

station (whose circuitry or logic has failed) that locks up the

network with its incessant transmission.

L

LAN Local Area Network.

Laser From Light Amplification by Stimulated Emission of Radiation. A

device that generates intense, directional light with a narrow range

of wavelengths. Laser light is coherent and thus does not disperse

easily, making it ideal for long-rang transmissions. Semiconductor

diode lasers are the standard light sources in fiber optic systems.

Compare with LED.


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LED Light Emitting Diode. A solid state device that emits light when

electrically stimulated. LED light is less coherent than laser light, isnot directional, and is more susceptible to dispersion..

Lightwave As an adjective, a synonym for optical, often (but not always)

meaning fiber optic.

Line overhead A part of the SONET overhead that is terminated by every network

element except regenerators. Compare with path overhead and

section overhead.

Loopstart

circuit

The standard world-wide telephone circuit. For a phone to signal

the telephone system that it wants to make a call, it applies a DC

termination across the phone line.

Loss budget An accounting of overall attenuation in a system.

Low speed data

module

A module that sends and receives data at sub-T1 speeds (under

1.544 Mbps). Intelect offers four low-speed data modules: RS-232,

RS-422, RS-449 and V.35.

M

Main controlcenter

The central location of network activities. This area usuallyincludes one NMS, fiber optic and analog patch panels, a

SONETLYNX node and network monitoring equipment. Each

SONETLYNX network will have a main control center.

Mapping The process of assigning SONETLYNX modules a specific location

within a network.

Master The point in a point-to-point or multidrop communication circuit

where communication begins and terminates. For some modules,

such as the RS-232, there must be a master module designated for

each circuit. Each circuit must have exactly one master.

Microwave A communication transport that uses electromagnetic radio waves.

Microwave is a common transport for voice and data applications.


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Modular A design that consists of plug-in units that can be added to a system

to increase capacity or functionality. The SONETLYNX system iscompletely modular, in that modules can be added or removed

without affecting the performance of other modules.

Module A piece of a modular system. SONETLYNX offers a variety of

modules that provide functionality to the SONETLYNX network.

Multidrop A communication protocol that includes many ports. One port is

designated as master and the remaining ports are designated

slaves.

Multi-mode

fiber

Fiber optic cable that has multiple light paths through the fiber.

Multiplexing The process of combining two or more signals to create a single

signal that can be broadcast across a network backbone.

N

Network One or more communication devices connected by a common

transport medium, such as fiber.

Networktopology

The way in which the fiber cable is physically laid out. The mostcommon topologies are linear, star and ring. Most SONET

networks are created using a ring topology.

NMS Network Management System. The SONETLYNX NMS operates

on top of HP OpenView.

Node A SONETLYNX chassis that is populated with controller modules,connected to the SONETLYNX network and mapped to a network

address. With split backplane shelves, a single chassis can contain

more than one node. Compare with chassis.

O

OAM&P Operation, Administration, Maintenance and Provisioning.


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OC controller The Optical Carrier (OC) Controller converts electrical STS signals

received from modules installed in the node into optical signals andtransmits them onto the network. It also decodes optical signals

received from the network and transmits them as electrical signals

to the modules installed in the node. Intelect offers OC-1 and OC-3

controller modules.

Optical carrier

levels

The optical carrier levels designate the speed at which the optical

carrier transmits data. Intelect offers OC-1 and OC-3 controller

modules.

Optical

interconnect

An interconnection unit used for circuit administration. Unlike an

optical cross-connect, the interconnection unit does not use patch

cords.

Overhead Transmission control information included with data sent on the

network. The overhead provides such information as mapping,message length and error checking.

P

Packetization The act of placing information in packets so that it can be sent

across the network. Ethernet LAN and ATM networks use

packetized information.

Paddleboard A piece of equipment used on the SONETLYNX node to connect the

customers external equipment to the network. Each SONETLYNX

module has at least one specific paddleboard.

Parity An error-checking method where the transmitting element counts

the number of 1s appearing in the data character and recordswhether that number is even or odd. When the signal is received,

the receiver also counts the number of ones and compares it to the

parity sent by the transmitter. If a single bit became corrupt, the

parity will not match.


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Patch panel A demarcation point between network equipment and the

customers external equipment. Patch panels allow maintenance tothe network without disturbing the customers external equipment,

and vice versa.

Path overhead A portion of the SONET overhead that is carried end-to-end and

only accessed by terminal multiplexers. The path overhead resides

inside the SPE. Compare with line overhead and section overhead.

Payload

envelope

The portion of the SONET transmission that involves the actual

data intended for the end user. SONET also carries overhead

information, that is used to facilitate network communication.

PBX Private Branch Exchange. A PBX is a privately owned, usually

smaller, version of a telephone company central office switch.

Plesiochronous Almost synchronous. If two networks are operating with clocks ofsufficient high quality such that the signals of the two systems are

nearly synchronous, the networks are plesiochronous.

Pointer A pointer indicates where the SPE begins within the SONET frame.

Because the SPE can float, depending upon timing variations, the

pointer may be in different locations from one frame to the next.

Point-to-point A communication protocol in which two modules are connected

directly to each other.

Private fiber

optic network

A fiber optic network that is privately owned and operated, as

opposed to a network that is owned and operated by the telephone

company.

Protect ring The secondary ring in a dual counter-rotating ring topology. Theprotection ring carries the same data as the working ring. It takes

over in case of a fiber break or network failure involving the

working ring.

Provisioning The process of defining the way that each module communicates

with other SONETLYNX modules and the external equipment

attached to it. Provisioning includes VT1.5 mapping, channel

configuration and alarm assignment.


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PTZ Pan, Tilt, Zoom. A common acronym referring to the ability to

remotely control pan, tilt and zoom functions of a video camera.The SONETLYNX video module provides PTZ functionality.

R

RBOC Regional Bell Operating Company. Often used as a synonym for

Local Exchange Carrier (LEC) or local telephone company.

Receiver A device that detects an optical signal and converts it into an

electrical form usable by other devices.

Redundancy Duplicating identical data on an alternate transport medium to

protect communications in the event of a network failure. For

example, in the SONETLYNX network, a redundant protect ring may

be installed in case the working ring malfunctions. On theSONETLYNX chassis, a redundant bus structure protects the

integrity of data being exchanged between modules in the same

node.

Regenerator Adigitalnetwork element that reproduces a received signal exactly

as it was received and transmits it. Regenerators allow digital

signals to travel beyond the range of the originating transmitter.

Compare with repeater.

Repeater An analog network element that retransmits a received signal

without modifying it. Repeaters allow analog signals to travel

beyond the range of the originating transmitter. Compare with

regenerator.

Ringinggenerator A device that provides ringing voltage to FXS-equipped voicemodules.

RJ-11 A modular 4-wire connector typically used with copper cable,

having two twisted pairs, usually unshielded. SONETLYNX uses

RJ-11 connectors on the voice module and the OC-1/OC-3

controller craft interface.


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Router Communications equipment that forwards information on a

connectionless basis. Routers maintain a routing table, whichcontains network topology information and an association between

destination addresses and physical ports (and perhaps virtual

circuits).

In complex networks, routers use routing protocols to exchange

network topology information with neighboring routers, so that the

routing table is kept current.

RS-232 A low-speed data protocol used to transfer data across the network.

SONETLYNX offers asynchronous RS-232 only.

RS-422 A low-speed data protocol used to transfer data across the network.

SONETLYNX offers asynchronous RS-422 only.

RS-449 A low-speed data protocol used to transfer data across the network.SONETLYNX offers synchronous RS-449 only.

S

S4 Intelects Special Services Switching System. A digital switch that

excels in mission-critical applications and multiple user conference

applications. The S4 is popular with air traffic control and airdefense industries.

Section

overhead

A portion of the SONET overhead that is terminated by every

network element. Section overhead controls framing and error

monitoring. Compare with line overhead and path overhead.

Single modefiber Fiber optic cable that contains only one light path through the fiber.

Slave A label used to designate a modules function in a point-to-point or

multidrop circuit. Modules must be designated as master and slave.

Each circuit can have multiple slaves, but only one master.


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SONET A North American standard for synchronous optical networks having

minimum transmission rates of 51.84 Mb/s. The standard SONETframe format for 51.84 Mb/s is called STS-1; the equivalent optical

transmission rate is called OC-1.

SONET standardizes not only these transmission bit rates, but also

overhead formats and other details of optical transmission to

accomplish mid-span meet between different vendors equipment.

SONETLYNX Intelects intelligent information transport platform for public and

private network applications. SONETLYNX offers OC-1 and OC-3

transmission equipment as well as a wide variety of channel cards

(modules) used to connect to customer external equipment.

SONETLYNX

network

A network comprised of SONETLYNX equipment.

Start bit In an asynchronous data stream, the start bit is used to indicated the

beginning of the payload data within each data character.

Stop bit In an asynchronous data stream, the stop bit is used to indicated the

end of the payload data within each data character.

STS-1 The standard SONET frame format for 51.84 Mb/s is called STS-1.

The equivalent optical transmission rate is called OC-1.


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Switch Generally, an electronic or mechanical device that makes, breaks, or

changes an electric connection.

In telephony, a device that connects incoming lines or trunks to

outgoing lines or trunks as part of an end-to-end connection.

Examples include: PBXs, LEC central offices and tandem/toll

switches and IEC switches (which are sometimes called central

offices).

In data communications, a device that routes data (such as a cell,

frame or packet) from one line to the next.

In networking, a device (such as a spanning-tree bridge) that detects

and breaks loops in Ethernet networks by disabling ports. The

network manager assigns a unique identifier and priority value to

each such bridge.

Synchronous A method of transferring data without the use of start bits and stop

bits. This requires the communication devices to derive their

internal clocks from a common source. Note that variations about

the average rate may occur and are referred to as jitter and/or

wander.

Synchronous

payload

envelope (SPE)

The portion of the SONET frame that contains the transmitted data.

The payload envelope can wander within the SONET frame, and is

identified by a pointer.

T

T1 A digital transmission system operating at 1.544 Mb/s typically

used to carry a DS1 signal format. In service since 1962, it operates

over two pairs of copper wire. Each wire pair is assigned a

different binder group and carries a signal in the opposite direction

of transmission..


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Time-division

multiplexing(TDM)

Digital multiplexing by taking one pulse at a time from separate

signals and combining them in a single bit stream.

Transceiver A combination of transmitter and receiver providing both output

and input interfaces with a device

Transport

overhead

1.728 Mb/s of bandwidth allocated within each SONET STS-1

channel to carry alarm indications, status information, and message

signaling channels for the preventive and reactive maintenance of

SONET transmission links.

Trip relay

alarm

An alarm which is triggered by breaking an electrical circuit.

SONETLYNX supports up to four trip relay alarms wired through

the OC-1/OC-3 controller.

U

Universal voice

module

The SONETLYNX voice module. It supports FXS, FXO and 4-wire

E&M protocols. Each module supports up to 8 distinct channels.

V

V.35 A low-speed data protocol used to transfer data across the network.

SONETLYNX offers synchronous V.35 only.

Virtual

tributaries (VT)

A SONET structure designed for the transport and switch of sub-

STS-1 payloads. There are currently four sizes of VTs defined:

VT1.5 (1.5 Mbps), VT2 (2 Mbps), VT3 (3 Mbps), and VT6 (6

Mbps).


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VT group Virtual tributary group. A SONET 9 row by 12 column (108 bytes)

structure that carries (byte interleaved)4 VT1.5s, or

3 VT2s, or

2 VT3s, or

1 VT6.

Seven VT groups (756 bytes) are byte interleaved within the VT

structured SPE.

VT mapping The process of assigning specific network addresses to each

configurable virtual tributary. SONETLYNX allows all modules to

be mapped from a central location.

W

Wan (wide area

network)

A computer or communications network that covers a geographic

area which is larger than a city or metropolitan area. TheSONETLYNX Ethernet module can be used to connect several

LANs, creating a WAN.

Wavelength-

division

multiplexing

(WDM)

Multiplexing of signals by transmitting them at different

wavelengths through the fiber.

Working ring The primary ring in a dual counter-rotating ring topology.

XILINX The brand name for the FPGA used by SONETLYNX.

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