IP Glossary Of Industry Terminology

10/100BASE-T
A LAN transmission line specification stipulated by IEEE. Transmission speed is 10 or 100 Mbps and the modulation technique is base-band modulation. The cable uses unshielded twisted pair, similar to a telephone wire.

A-law
The PCM coding and compression standard used in Europe and in areas outside of North America influence. A Law Encoding is the method of encoding sampled audio waveforms used in 2.048Mbps, 30 channel PCM primary system known as E-carrier.

AGC
Automatic Gain Control is a feature of IP solutions units that allows the units to automatically adjust the incoming voice signal to a user defined level in dBm.

Audible Signal Tones
Identification tones used to control the connection process or provide status to telephone calling and called parties. The tones include dial tone (DT), busy tone (BT), ring-back tone (RBT), special dial tone (SDT), connection restriction tone (RDT), howler tone (HWT), and ring (RI).

Audio Processing
A technology which addresses the control, transmission, storage, and recreation of sound, including the human voice.

Auto Answer
The capability of a machine to answer a ringing telephone without  human intervention.

Autodial
An auxiliary device for a telephone that automatically dials any of a  group of prerecorded telephone numbers.

Automatic Drop Out
A function that automatically stops sending the ringing signal to the called side and automatically returns the line to an idle state when a received call is terminated by the calling party.

Call Signaling Channel
H.323 reliable channel used to convey call setup messages following the Q.931 protocol.

Communication Service
One category of service functions supported by IP Solutions. The telephony communication, including fax communication, supported by IP Solutions can be generalized, from the connection configuration point of view, in inter-extension communication, through IP network and communication via PBX. This category of service functions includes functions corresponding to each type of communication.

Communication Through IP Network
One of the service functions supported by IP Solutions. It provides a mutual communication, through the IP network, among the terminals (ordinary analog telephone set, G3 fax machine) connected directly to other IP Solutions products.

Communication Through PBX
One of the services supported by IP Solutions. Terminals (ordinary telephone set, G3 fax machine) connected to VIP810 can communicate mutually and also with the terminals accommodated directly in VIP820.

Delay-Start
A PBX startup method (timing method) used by IP Solutions. Delay-start is the time from PBX startup to the arrival of a selection. The pre-pause method is used to perfect receive operation of selection signal or to perfect a PBX connection by the selection signal.

Digital-to-Analog Converter
A device that converts digital signals to analog signals.

Direct Inward Dialing
A Centrex feature that allows an outside caller to dial a central business number, as well as an extension number.

DNS (Domain Name System)
DNS is a distributed data base system that stores IP addresses and corresponding domain names. The DNS was originated to represent IP addresses such as 202.203.90.60 used over the IP network, by easy to understand names. Typically one or more DNS servers is located in an IP network.

DNS Function
For IP Solutions, a function that manages translation information that converts a dialed number (identification number assigned to each unit) to a number that represents the IP address of a called unit. Typically, a translator is placed in the DNS server located in a network, and a unified numbering management (integrated management) is implemented. When a DNS server is not used, translation data is stored by IP Solutions units.

DNS Information
A number dialed by a telephone set is changed to an IP address using the DNS (Domain Name System). The IP address is the number used to actually set up a call over a voice network.

Endpoint
A Terminal Gateway or MCU in an H.323 network.

Gatekeeper
An H.323 entity that provides address translation, control access, and sometimes bandwidth management to the LAN for H.323 terminals, Gateways, and MCUs.

Gateway
An H.323 entity which provides real-time, two-way communications between two H.323 endpoints.

H.323 Entity
Any H.323 component, including terminals, Gateways, Gatekeepers, MCs, MPs, and MCUs.

H.245 Logical Channel
A channel carrying information streams between two H.323 endpoints.

Inter-Extension Communication
One of the service functions offered by VIP810. Ordinary analog telephones can be directly accommodated by VIP810 units and can be linked with each other.

IP (Internet Protocol)
IP protocol is widely used in Internet and LAN networks. The purpose is to deliver data between computing equipment over the network. The protocol is generally effective but does not guarantee complete and accurate data communications.

IP Address
A number used to identify the location of a host device. It is expressed in numeric dot notation (e.g. 202.203.27.31).

Local Area Network
A shared or switched medium, peer-to-peer communications network which may include inter-networks composed of LANs connected by bridges or routers.

Jitter
Jitter refers to fluctuations in transmission delay time. In the case of voice data, conversations are packaged into packets (IP packetization) and transmitted. Individual packets can take different routes through the varied networks that comprise the Internet. When the time interval for the arrival of the packets is not constant the timing fluctuations that may occur are referred to as "jitter".

Key Telephone System
A telephone exchange that presents the Central Office trunk lines to the telephone and allows access to these trunks with keys on the telephone set.

Line Data
Line data is a category of office data that includes both terminal and trunk data.

M-Law
The PCM voice coding and compression standard used in Japan and North America. A PCM encoding algorithm where the analog voice signal is sampled eight thousand times per second, with each sample being represented by an eight bit value, thus yielding raw 64kbps transmission rate. A sample consists of a sign bit, a three-bit segment specifying a logarithmic range, and a four-bit step offset into a range. All bits of the sample are inverted before transmission.

Numbering Plan
In a communications network, a numbering plan allocates specific numeric codes to identify each subscriber line, special lines, trunk lines, etc. Numbering plans can be divided into the numbering system and number assignments. The numbering system indicates the number of digits to be assigned and the basic scheme of number assignment. The assignment of specific codes is performed according to the numbering system.

Numbering Plan Data
Numbering plan data is a category of office data. It includes both numbering plan and routing information.

PCM (Pulse Code Modulation)
The most common digitization technique for encoding an analog voice signal into a digital bit stream. The most common PCM method is to sample a voice conversation at 8000 times per second. The theory is that if the sampling is at least twice the highest frequency on the channel, which produces satisfactory voice tones.

Port Number
A port number is a logical number that manages the category of service supported and resources used in the TCP/UDP protocol. The port number is referred to when setting the priority control of a router.

Priority Connection Information
In IP Solutions, DNS information stored in the unit is referred to as priority connection information. During call connection, this database is queried before the unit cache and DNS servers.

Priority Control
When a packet to which a high priority indication flag has been assigned is sent, the packet is transferred with priority. The priority control function is used in a router or an exchange in order to minimize delay time. Voice or fax communication, in a network not using priority control, may be interrupted when network traffic increases.

Private Branch Exchange (PBX)
A telephone exchange that services an individual organization and had connections to a public telephone exchange.

PSTN
Public Switched Telephone Network

Q.931
H.323 signaling protocol for setup and termination of calls.

RAB
Reserve Bandwidth Control is a Gatekeeper function that allows the system administrator to reserve bandwidth for applications other than VOIP.

RAS Channel
An unreliable channel used to convey the Registration, Admissions, and Status messages and bandwidth changes between two H.323 entities.

Reliable Transmission
Connection-oriented data transmission that guarantees sequenced, error-free, flow-controlled transmission of messages to the receiver.

Real-Time Protocol/Real-Time Control Protocol (RTP/RTCP)
IETF specifications for audio and video signal management. Allows applications to synchronize and spool audio and video information.

Remote Maintenance
One of the service functions supported by IP Solutions. All IP Solutions Products can be maintained remotely over a network connection. The VIP100 software supports remote maintenance functions.

Session Initiation Protocol SIP
The Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol for creating, modifying, and terminating sessions with one or more participants. These sessions include Internet telephone calls, multimedia Audio distribution, and multimedia conferences.

TCP
Transmission control protocol. A reliable networking layer on top of IP.

Terminal
An H.323 endpoint which provides for real-time, two-way communications which another Terminal, Gateway, or MCU. A terminal must provide audio and may also provide video and/or data.

Terminal Mode
Terminal mode is one of the operational modes of the VIP100 Maintenance Console Software. The terminal mode includes functions like LAN maintenance, emergency maintenance, and FTP client startup.

Trunk Line
A telephone communications channel between two switching stations or between PBX switching stations and a Central Office.

UDP
User Datagram Protocol. An unreliable networking layer that sits at the same level of the networking stack at TCP.

Unreliable Transmission
Connection-less transmission which provides best-effort delivery of data packets. Messages transmitted by the sender bay be lost, duplicated, or received out of sequence.

Voice-over-Internet-Protocol
(VoIP) is an emerging technology that allows telephone calls, faxes, or overhead paging to be transported over an existing IP data network topology.

Voice Compression
A high-quality voice compression function is incorporated in IP Solutions to achieve voice communication through the IP network. At the calling side, voice is compressed to 8 Kbps digital signal and then packaged (IP packetization) and delivered to a router for transport across the network. On the receiving side, other IP solution units reassembles the IP packets and restores them to the digital signal. The original voice is regenerated by expanding (decompressing) the restored digital signal.

Wink-Start
One of the PBX startup methods (timing methods) employed by IP Solutions. A short off-hook pulse is sent to PBX to notify it that the equipment is ready to receive digital information from the calling side. PBX controls the startup by this pulse. The timing of the pulse width can be changed at wink start.

Zone
A collection of all H.323 Terminals, Gateways, and MCUs managed by a single H.323 Gatekeeper. A zone must include at least one Terminal and may include LAN segments connected using routers.