The vocabulary of a telephony quotation, in plain words.

ACDAutomatic call distribution

The mechanism that chooses who to hand a call in a queue to: longest idle, most skilled, or first available. It is what separates a queue from a general ring, and it is where the wait time you actually hold to is decided.

CodecAudio coder-decoder

The algorithm that compresses speech to fit it on the network. G.711 barely compresses and sounds good if there is bandwidth; Opus adapts to whatever is left when the link degrades. A badly chosen codec only shows up at the moment the line tires.

CTIComputer telephony integration

The fact that the call and the business software talk to each other: the customer’s record opens when they ring, the call is placed from the CRM, the write-up goes back into the tool. See the integrations.

DDIDirect dial-in

A public number that reaches a person or a department directly without going through the main number. A company buys a block of them, and the dialling plan says which number lands where.

DECTDigital cordless telephony

Cordless for the sites where a mobile will not do: warehouses, kitchens, workshops, healthcare premises. One base, handsets that follow it from cell to cell without dropping the call.

DTMFTouch tones

The tones sent when you press a digit during a call — “press 1 for”. They now travel outside the audio (RFC 2833) rather than inside it, which stops a compressing codec making them inaudible to the machine at the other end.

E.164International number format

The canonical way to write a number: a plus, the country code, the rest, with no spaces and no leading zero — +33123456789. Any contact database that mixes formats eventually rings the wrong number from abroad.

EdgeLocal switching appliance

A device placed on the site that switches internal calls locally. The handsets keep ringing each other when the internet link drops, because the cloud is not on the critical path. See Konvoice Edge.

ExtensionShort internal number

The short number of a person or a department inside the company — 1001. It belongs to the person, not to the device: the same extension rings on the desk phone, the computer and the mobile.

FXO / FXSAnalogue interfaces

Two sockets that look alike and do different things. FXO plugs into an analogue line from the carrier — that is a backup line; FXS feeds an analogue handset, a fax or a door entry panel.

Hold musicMOH

What the caller hears while waiting. An announcement giving the position in the queue or the estimated wait changes the abandon rate far more than the music itself does.

IP PBXIP private branch exchange

The phone system when it is software rather than a cabinet. Konvoice is one, served from the cloud, with a local relay for what must not depend on the link.

IVRInteractive voice response

The greeting menu: “for sales, press 1”. A good IVR has two levels at most and a way out to a human on every level. See the phone system.

JitterDelay variation

The variation in delay between two speech packets. A long but steady delay is barely audible; an irregular one chops speech up. It is the measurement that best explains “it keeps breaking up” when the throughput is fine.

MOSMean opinion score

A score from 1 to 5 summarising the perceived quality of a call, computed from loss, jitter and delay. It is for comparing two links or two moments, not for describing one particular conversation.

Non-geographic number08, 09, special numbers

A number that does not designate a town. Some are premium-rate for the caller, which shows up on a bill and gets held against a brand; others are not. The difference is in the prefix, and it has legal consequences.

PBXPrivate branch exchange

The ancestor: the telephone cabinet in a plant room, with its cards and its maintenance contract. What an IP PBX replaces, and whose dialling plan a migration must carry over unchanged.

PortingKeeping your number

The right to take your number to another carrier. The operation is regulated and dated; what has to be prepared is the switchover — so that the phone system does not go down during it. See numbers and carriers.

ProvisioningAutomatic configuration

A phone that comes out of the box, plugs in, and receives its number, its display name, its keys and its firmware on its own. The alternative — typing SIP credentials by hand on every handset — does not scale and leaves passwords lying about. See the devices.

PSTNPublic switched telephone network

The historic copper network. Its shutdown is under way in most of the countries we operate in: analogue lines and ISDN accesses are no longer sold and are being switched off area by area. It is the calendar reason behind most migrations.

QoSQuality of service

The network setting that gives voice priority over everything else. Without it, a backup started at midday degrades every call on the site, and nobody connects the two.

QueueCall queue

A group of people, a distribution rule and a patience. What matters is not the queue itself but what it does when it overflows: overflow to another group, automatic callback, voicemail, or a divert.

SBCSession border controller

The device that guards the border between the carrier’s network and yours: it normalises SIP, encrypts what has to be encrypted and stops what has no business being there. It is also the first defence against termination fraud.

SIPSession initiation protocol

The protocol that opens, transfers and ends a call. It does not carry the voice: it negotiates, and the voice then travels over RTP. A great many faults described as “voice” faults are in fact SIP faults.

SIP trunkInterconnection trunk

The link between your phone system and a carrier, carrying inbound and outbound calls and a maximum number of simultaneous calls. You can have several, with several carriers, and switch between them.

SoftphoneThe phone that is not an object

An application on a computer, a mobile or in a browser. It carries the same number as the physical handset and the same history. The Konvoice apps are one.

SRTP / TLSEncrypting voice and signalling

TLS encrypts SIP signalling, SRTP encrypts the voice stream. Either without the other leaves the content or the metadata exposed. See the security note.

STIR / SHAKENCalling number authentication

The mechanism that signs the displayed number so the terminating carrier knows it has not been falsified. It is the regulatory answer to caller ID spoofing, and it changes what a company is allowed to present on outbound calls.

T.38Fax over IP

The protocol that carries a fax over an IP network without transporting it as sound. It is still needed wherever fax is a legal requirement — healthcare, notaries, public administration — and it is the first thing a migration forgets.

Voice VLANVirtual LAN dedicated to voice

A separate network, on the same cable, for the telephones. It lets you give them priority and isolate them from the workstations: a compromised computer then has no telephones within reach.

VoIP telephonyTelephony over IP

Business telephony when it travels over the data network rather than over dedicated copper pairs. Distinct from VoIP the technique; the service is the whole thing — handsets, phone system, queues, logs.

WebRTCReal-time communication in the browser

What lets a browser tab make a call with no plug-in to install. It is the technique behind the Konvoice workspace in the browser — open it with nothing installed.

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