Plain-English telecom terms for technology providers.

PBX

Private branch exchange: the system that manages an organisation’s extensions, call routing, voicemail, queues and connections to the public phone network. It may be cloud-hosted, software-based or an on-site appliance.

Cloud PBX

A phone system delivered as a hosted service instead of being run on hardware at the customer’s premises. Users typically connect through desk phones and web, desktop or mobile clients. See TeraFi Cloud PBX.

UCaaS

Unified communications as a service. A cloud subscription that can combine business calling, presence, messaging, meetings and related collaboration features.

SIP

Session Initiation Protocol: a common signalling standard used to start, manage and end voice or video sessions over IP networks.

SIP trunk

An IP-based connection that carries calls between a compatible PBX and a telephony provider. Capacity is commonly described in simultaneous call channels. Explore SIP trunking.

Extension

A user, phone, room or function inside a PBX with its own internal identity and calling permissions. An extension does not always need a separate public phone number.

IVR

Interactive voice response: a menu that asks callers to choose options using keypad input or, on some systems, speech. It is often used to route calls by team, purpose, language or account type.

Auto-attendant

An automated greeting and routing function. In everyday use the term overlaps with IVR, although an auto-attendant may provide simpler menu and transfer behaviour.

Ring group

A call-distribution rule that alerts several extensions at once or follows a defined order when a shared number or function receives a call.

Call queue

A waiting line for callers when the relevant agents are busy. Queue systems can include announcements, priority rules, callbacks, reporting and supervisor tools.

Softphone

An application that lets a computer, browser or mobile device act as a business phone. Yeastar’s user clients are called Linkus. See the Yeastar partner hub.

Codec

A method for encoding and decoding audio. Codec choice affects bandwidth use, compatibility and perceived call quality.

NBN

Australia’s wholesale broadband access network. Available technologies and achievable performance vary by address and service class.

Enterprise fibre

A business connectivity service designed around dedicated or committed performance and stronger operational requirements than a typical broadband service. Exact inclusions vary by carrier and product.

Failover

A backup path used when the primary service is unavailable. For internet access this may be a second fixed link or a mobile service connected to a suitably configured router.

Static IP address

An internet address intended to remain consistent, commonly used where remote access, allow-lists, hosted services or specific network designs require it.

IoT / M2M SIM

A SIM used to connect equipment rather than a person’s everyday phone—for example routers, sensors, terminals, signage, lift phones or tracking devices.

Data pooling

An arrangement where multiple mobile services draw from a shared data allowance rather than each service having an entirely separate allocation.

Provisioning

The controlled work required to create, configure, activate and record a service so it is ready for use.

MACD

Moves, adds, changes and disconnects: the routine service requests that continue after the initial installation.

Service level

A defined service commitment or target covering matters such as availability, response or restoration. Marketing language should not be treated as a contractual service level unless it appears in the applicable agreement.

Escalation

The process of moving an issue to a team or supplier with the authority, access or expertise required to progress it.

Carrier

An organisation that operates telecommunications network infrastructure or carriage services. A reseller or aggregator may supply carrier-backed services without being the underlying network operator.

CIS

Critical Information Summary: a standardised summary used for certain telecommunications offers in Australia. The correct document and obligations depend on the service and sales context.

Use this page as an orientation guide. Contractual, regulatory and technical meanings can be more specific. Check the applicable service schedule, agreement, carrier documentation and legal requirements before relying on a definition for a decision.