The glossary
101 terms that come up when you automate a phone line, defined plainly.
20 terms
IVR
Interactive Voice Response — the keypad menu system.
DTMF
The tones a phone sends when you press a key.
SIP
The signalling protocol that sets up internet calls.
SIP trunking
Connecting a phone system to the network over the internet.
VoIP
Voice calls carried over an internet connection.
PSTN
The traditional switched telephone network.
DID
A direct-dial number that reaches a specific destination.
Area code
The prefix that identifies a number's geographic region.
Toll-free number
A number the receiving business pays for.
Local presence
Using a local number so callers recognise the code.
Caller ID
The number, and sometimes name, shown to the person you call.
Branded calling
Showing your business name on the recipient's screen.
Spam likely
The carrier warning shown on suspected nuisance calls.
Concurrent calls
How many calls can be in progress at once.
RTP
The protocol that carries the actual call audio.
Jitter
Variation in packet arrival time, heard as choppy audio.
Packet loss
Audio packets that never arrive.
Auto attendant
An automated answer that directs calls.
Call forwarding
Sending calls from one number to another.
Failover
The fallback path when the primary one fails.
31 terms
Voice agent
Software that holds a spoken conversation on a call.
Conversational AI
Systems that hold a natural back-and-forth exchange.
ASR
Automatic Speech Recognition — turning speech into text.
STT
Speech to text; used interchangeably with ASR.
TTS
Text to speech — generating the agent's voice.
LLM
The language model that decides what the agent says.
System prompt
The written instructions that define an agent's behaviour.
Function calling
Letting the model trigger real actions.
Tool use
A model acting through external systems.
Knowledge base
Your own material the agent answers from.
RAG
Retrieving relevant material before answering.
Grounding
Tying answers to source material.
Hallucination
A confident answer that is not true.
Guardrails
Constraints on what an agent may say or do.
Prompt injection
Input crafted to override an agent's instructions.
Latency
The delay before the agent starts replying.
Time to first token
How long until a model starts producing output.
Streaming
Processing audio and text as they arrive.
Turn taking
Deciding when the caller has finished speaking.
Endpointing
Detecting the end of a caller's utterance.
VAD
Voice Activity Detection — telling speech from silence.
Barge-in
Letting a caller interrupt the agent mid-sentence.
Noise suppression
Removing background sound from call audio.
Diarization
Working out who spoke when.
Transcription
The written record of what was said.
Voice cloning
Synthesising a specific person's voice.
Prosody
Rhythm, stress and intonation in speech.
Context window
How much the model can consider at once.
Chatbot
A text-based conversational interface.
Webhook
An HTTP callback that delivers events to your system.
API
A programmatic interface to a service.
22 terms
Call routing
Directing a call to the right destination.
Skills-based routing
Matching callers to agents by capability.
Warm transfer
Handing over a call with context.
Cold transfer
Handing over a call with no briefing.
Handoff
Passing a conversation from agent to human.
Escalation
Moving a call to someone with more authority.
Queue
Callers waiting for the next available person.
Overflow
Handling calls beyond normal capacity.
After-hours answering
Covering calls outside business hours.
Answering service
A third party answering calls on your behalf.
Virtual receptionist
A remote or automated front desk.
Outbound dialling
Calls placed by the business.
Predictive dialer
Dialling ahead of agent availability.
Batch calling
Running a list of outbound calls as a campaign.
Voicemail detection
Telling an answering machine from a person.
Voicemail
Recorded messages from callers.
Post-call analysis
Reviewing what happened after a call ends.
Quality assurance
Checking that calls meet a standard.
Sentiment analysis
Estimating how a caller felt.
CRM
The system of record for customer relationships.
Lead capture
Recording a prospect's details and intent.
Lead qualification
Deciding whether a lead is worth pursuing.
15 terms
STIR/SHAKEN
The framework that cryptographically attests caller ID.
TCPA
US law restricting automated calls and texts.
Do Not Call
Registries of numbers that must not be solicited.
Consent
Permission to contact or to record.
Two-party consent
Where everyone on a call must agree to recording.
Call recording
Storing the audio of a conversation.
Data retention
How long records are kept before deletion.
PII
Information that identifies a person.
Redaction
Removing sensitive detail from records.
GDPR
EU regulation governing personal data.
HIPAA
US rules for protected health information.
PHI
Health information tied to an individual.
PCI DSS
Security standard for card payment data.
SOC 2
An audited report on a service provider's controls.
AI disclosure
Telling callers they are speaking to a machine.
13 terms
Word error rate
How often speech recognition gets words wrong.
Containment rate
Share of calls resolved without a human.
Deflection
Diverting contacts away from live agents.
First call resolution
Share of issues solved on the first call.
Repeat call rate
How often callers come back about the same thing.
Abandonment rate
Share of callers who hang up before being answered.
Average speed of answer
How long callers wait before being answered.
Service level
Share of calls answered within a target time.
Average handle time
Mean duration of a handled call.
CSAT
Customer satisfaction, usually a post-contact score.
NPS
Net Promoter Score — likelihood to recommend.
Call volume
How many calls arrive over a period.
Uptime
Share of time a service is available.
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