Glossary · 55 terms
CPaaS & channels
Communications Platform as a Service beyond WhatsApp: SMS and its encodings, India's DLT framework, RCS business messaging, voice and IVR, email, sender identities and the omnichannel orchestration that routes each message to the right channel.
Foundation· 21
Start here — the concepts everything else builds on.
- Application-to-Person SMSA2PSMS sent by software rather than a person, such as OTPs, alerts and promotions, routed, priced and regulated apart from person-to-person texts.Read definition
- Cloud TelephonyA business phone system hosted in the cloud, with virtual numbers, IVR, call routing and recording, rented as a service instead of an on-site PBX.Read definition
- Communications Platform as a ServiceCPaaSCloud APIs that let developers build SMS, voice, WhatsApp, RCS and email into their own software, paid per use instead of running telecom infrastructure.Read definition
- DLT RegistrationDLTOnboarding on India's DLT platform, registering the business, its headers, content templates and consent templates before any commercial SMS is sent.Read definition
- DND Registry (NCPR)NCPRIndia's National Customer Preference Register, where users block promotional calls and SMS fully or by category by dialling 1909 or using an app.Read definition
- Interactive Voice ResponseIVRAn automated phone menu callers steer by keypress or voice to serve themselves or reach the right team, often with an option to move to WhatsApp.Read definition
- Long Code (Virtual Mobile Number)VMNA standard-length mobile number, known in India as a virtual mobile number, used for two-way business SMS at lower throughput than a short code.Read definition
- Missed Call ServiceA number that rejects incoming calls and replies by SMS or WhatsApp, so people can opt in or request details at no cost, even from a feature phone.Read definition
- MO vs MT MessagesCarrier terms for message direction: mobile-originated messages go from a user to a business, mobile-terminated ones from a business to a user.Read definition
- Multimedia Messaging ServiceMMSCarrier picture, audio and video messaging sent through the mobile network, with tight size caps and patchy support outside North America.Read definition
- OTT MessagingOTTMessaging apps such as WhatsApp that run over the internet on top of carrier networks, so the app owner, not the carrier, sets the rules.Read definition
- Public Switched Telephone NetworkPSTNThe traditional public telephone network, now largely IP at its core, where voice calls, voice OTPs and flash calls ultimately ring through.Read definition
- Push NotificationAn alert an app sends to a phone through the operating system's push service, reaching only people who installed it and allowed notifications.Read definition
- RCS Business MessagingRBMCarrier-delivered business messaging in the phone's built-in messages app, with a verified sender, rich cards, carousels and suggested replies.Read definition
- Sender IDThe name or number a recipient sees as the sender of an SMS: an alphanumeric label, a long code or a short code, governed by each country's rules.Read definition
- Short CodeA five- or six-digit number leased for high-volume two-way SMS, keyword campaigns and inbound replies, faster to send from than a long code.Read definition
- Short Message ServiceSMSThe carrier text channel that delivers short messages to any mobile phone through the operator's message centre, with no app or data needed.Read definition
- SMS GatewayA service that turns API requests into carrier SMS traffic, choosing routes and returning delivery reports to the sending application.Read definition
- SMS OTPA one-time passcode sent by text message to verify a user, simple and universal but exposed to SIM swaps, delivery delays and SMS pumping fraud.Read definition
- Unstructured Supplementary Service DataUSSDSession-based *123# menus sent over mobile signalling that work on any phone without data, used for balance checks and UPI payments via *99#.Read definition
- WhatsApp vs SMSA head-to-head of WhatsApp and SMS for Indian businesses on reach, cost, delivery and read signals and rich media, including where SMS still wins.Read definition
Practitioner· 27
What you need once you are running it day to day.
- A2P 10DLC10DLCThe US scheme for business texting from ordinary 10-digit numbers, which requires brands and campaigns to register with carriers before sending.Read definition
- Concatenated SMSA long SMS split into segments of up to 153 GSM-7 or 67 UCS-2 characters, which a header lets the phone rejoin, each billed as a separate message.Read definition
- Contact Center as a ServiceCCaaSA cloud contact-centre suite with call routing, IVR, agent desktop, workforce management and analytics, bought as a finished application.Read definition
- DLT Content TemplateSMS wording registered in advance on India's DLT platform, with placeholders and a category, whose template ID every send must carry.Read definition
- DLT HeaderThe sender ID a business registers on India's DLT platform to appear on its SMS, whose format and category suffix depend on the message category.Read definition
- DLT Message CategoryIndia's DLT classes for commercial SMS (transactional, service implicit or explicit, and promotional) that set consent, DND and sending-hour rules.Read definition
- DLT ScrubbingThe real-time check an Indian operator runs on each commercial SMS against its registered header, template, consent, DND and delivery chain.Read definition
- DLT URL WhitelistingThe TRAI rule that blocks commercial SMS containing URLs, APK or OTT links that have not been whitelisted on the sender's DLT account.Read definition
- Email BounceAn email returned undelivered, either a hard bounce for a permanent failure such as a bad address or a soft bounce for a temporary one.Read definition
- Fallback ChannelA second channel, usually SMS, that a message is re-sent on when WhatsApp reports it failed or it stays undelivered past a set timer.Read definition
- Flash Call VerificationVerifying a phone number with a missed call that drops before it is answered, whose caller ID digits serve as the one-time code.Read definition
- Grey RouteAn unofficial SMS path through SIM boxes or unauthorised interconnects that looks cheap but loses delivery reports, sender IDs and compliance.Read definition
- GSM-7 EncodingGSM-7The default 7-bit SMS alphabet of Latin letters, digits and common symbols, fitting 160 characters in one message or 153 per segment of a longer one.Read definition
- HLR LookupHLRA pre-send query to a mobile network's Home Location Register showing whether a number is valid, active, roaming or ported, and on which operator.Read definition
- Instagram Messaging APIMeta's API for managing Instagram professional-account DMs, including story and comment replies, with its own messaging window and identity rules.Read definition
- Messenger PlatformMeta's API for messaging people on Facebook Messenger from a Page, using page-scoped IDs and a 24-hour standard messaging window.Read definition
- Number MaskingProxy phone numbers that connect two parties, such as a rider and driver, by call or SMS without either seeing the other's real number.Read definition
- Omnichannel OrchestrationChoosing the best channel for each user, message and moment across WhatsApp, SMS, RCS, email and voice while keeping one customer context.Read definition
- Principal EntityPEThe business registered on India's DLT platform as the sender of record, whose PE ID owns its SMS headers, content templates and consent templates.Read definition
- RCS AgentThe verified, branded sender in RCS Business Messaging, with a name, logo and colours, approved by each carrier before it can message users.Read definition
- Simple Mail Transfer ProtocolSMTPThe protocol mail servers use to relay email from sender to recipient, with commands such as MAIL FROM, RCPT TO and DATA, and STARTTLS for encryption.Read definition
- SMS Delivery ReportDLRThe carrier receipt for an SMS, with states such as delivered, undeliverable, expired or rejected, but no signal that the message was read.Read definition
- SMS Pumping (Artificially Inflated Traffic)AITFraud in which bots trigger OTP or sign-up SMS to number ranges whose termination revenue the fraudsters share, inflating the sender's bill.Read definition
- SPF, DKIM and DMARCThree DNS-based email authentication standards that list authorised senders, sign messages and set a policy for failures, guarding inbox placement.Read definition
- TCCCPR (Telecom Commercial Communications Customer Preference Regulations)TCCCPRTRAI's 2018 regulations, since amended, that govern unsolicited commercial calls and SMS in India and form the legal basis of DLT and DND preferences.Read definition
- UCS-2 EncodingUCS-2The 16-bit SMS encoding for Hindi and other scripts, emoji and curly quotes, which cuts a message to 70 characters, or 67 per segment.Read definition
- Voice Broadcast (OBD)OBDAn outbound dialler campaign that plays a recorded or text-to-speech message to a large list of numbers and captures keypress responses.Read definition
Expert· 7
Edge cases, internals and the details that matter at scale.
- Digital Consent AcquisitionDCAA TRAI-mandated, operator-run system in which customers confirm or revoke consent to a brand's promotional SMS and calls via a common short code.Read definition
- Least-Cost RoutingLCRThe logic an SMS or voice platform uses to pick an operator route per destination by price, delivery rate and latency, risky if price alone decides.Read definition
- PE-TM Chain BindingThe TRAI requirement that every commercial SMS follows a pre-declared chain from the sending business through each telemarketer, so it can be traced.Read definition
- Session Initiation ProtocolSIPThe signalling protocol that sets up, changes and ends internet voice calls and links business phone systems to carriers through SIP trunks.Read definition
- Short Message Peer-to-Peer ProtocolSMPPThe binary protocol that applications use to send and receive high volumes of SMS through an operator's message centre over a persistent connection.Read definition
- Silent Network AuthenticationSNAVerifying a phone number by having the mobile operator confirm the SIM behind the device's data connection, with no code for the user to type.Read definition
- WebRTC (Web Real-Time Communication)WebRTCThe open standard for real-time audio, video and data in browsers and apps, with built-in NAT traversal and encryption, used for WhatsApp calling.Read definition
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