Telephony and infrastructure

Audio codecs

An audio codec is the scheme that squeezes sound into a form a network can carry, and whichever one a voice system runs on settles how the audio sounds, what it costs in bandwidth, and how much of it a recognizer can actually transcribe.

Call routing

Call routing is the logic that sits between a call arriving and someone answering it, deciding which queue, agent, department or automated system the call should reach, and an AI voice agent typically joins that logic as one of its destinations rather than replacing it.

Cold transfer

A cold transfer, also called a blind transfer, passes a call to another destination with no context and no briefing, forcing the caller to re-establish their identity, problem and history; it is the default behavior whenever context passing is not deliberately built.

Concurrency

Concurrency counts the conversations a voice system can run at once, which makes it a question about capacity rather than about volume, and it governs what happens on the busiest day instead of the ordinary one.

Contact center platform

A contact center platform is the system that runs customer contact operations, meaning routing, queuing, agent management, recording, reporting and workforce scheduling, and it is the incumbent estate an AI voice agent has to work alongside rather than replace.

CPaaS

CPaaS, Communications Platform as a Service, is an API that lets software make calls, send messages and handle voice without the business negotiating with carriers or navigating numbering regulation in every market itself.

DTMF

DTMF, dual-tone multi-frequency, is the touch-tone scheme that turns every keypad press into its own pair of tones, and it remains the right way to collect the card numbers, PINs and reference codes that speech recognition reliably mangles.

Inbound vs outbound agents

An inbound voice agent answers contacts that come to the business while an outbound agent initiates contact, and although they share the same technology they differ so much in regulation, deliverability, intent and economics that they are substantially different businesses.

Number provisioning

Number provisioning is obtaining and configuring telephone numbers for a service, and because numbers are regulated resources allocated through national numbering plans, it is geography-specific and slower than most software teams expect.

PSTN

The PSTN, or Public Switched Telephone Network, is the worldwide arrangement of carriers, numbering plans and interconnect deals that lets any phone number dial any other, and the narrowband audio it carries holds measurably less information than a browser microphone captures.

SIP and SIP trunking

SIP, the Session Initiation Protocol, is what phone systems use to open, manage and close voice calls across internet networks, and SIP trunking is the service you buy to reach the outside telephone network through an internet connection rather than through physical lines into the building.

Softphone

A softphone is telephone software running on a computer or mobile device in place of a physical handset, and in voice AI it matters as the surface where a human agent receives an escalation and where the AI conversation context has to appear.

STIR/SHAKEN and spam-likely labeling

STIR/SHAKEN is a framework that lets carriers cryptographically verify a call really originates from the number it claims, while spam-likely labeling is a separate and proprietary scoring layer that decides whether a warning appears on the recipient screen.

Telephony provider and carrier

A carrier operates telephone network infrastructure and terminates calls, while a telephony provider is whoever a business buys voice service from, which may be a carrier or a reseller sitting above one, and the route between them determines cost, audio quality and attestation.

Warm transfer

A warm transfer passes a conversation to a person along with everything already known about it, so the receiving human arrives informed and the customer does not have to repeat themselves; the defining property is the completeness of the context, not the speed of the handoff.

WebRTC

WebRTC is a set of open browser standards for capturing, processing and transporting live audio and video in real time, and it is what lets a website hold a spoken conversation with no plugin, no app and no phone call.