27 Terms Explained
Bulk Messaging Glossary
Plain-English definitions of every term you will meet in bulk SMS, WhatsApp marketing and Indian telecom compliance — DLT, sender IDs, OTP routes, RCS and more.
- Bulk SMS
- Sending a text message to many recipients at once through a messaging platform or API, used for promotions, alerts, reminders and OTPs. In India, bulk SMS operates under TRAI's DLT framework.
- DLT (Distributed Ledger Technology)
- TRAI-mandated registration system for commercial SMS in India. Businesses register their identity, sender IDs and message templates on an operator DLT portal; unregistered traffic is blocked.
- Sender ID (Header)
- The 6-character brand name (like GURSMS) shown as the sender of your SMS instead of a phone number. Must be registered and approved on DLT before use.
- Content Template
- The exact, pre-approved wording of a commercial SMS registered on DLT, with variables marked as {#var#}. Messages must match a registered template or operators drop them.
- Transactional SMS
- Critical, non-marketing messages like OTPs and bank alerts. They ride a priority route, are delivered 24x7, and reach DND-registered numbers.
- Promotional SMS
- Marketing and offer messages. They use a separate route, respect DND preferences, and can be delivered only between permitted hours (roughly 10 AM to 9 PM).
- Service Explicit / Implicit
- DLT sub-categories: service-implicit covers expected updates (order status, reminders); service-explicit covers promotional content sent to your own opted-in customers.
- OTP (One-Time Password)
- A short-lived numeric code sent by SMS, WhatsApp or voice call to verify a user's phone number, login or transaction. Delivered on dedicated transactional routes in seconds.
- A2P Messaging
- Application-to-Person messaging — texts sent from software (a website, app or CRM) to a person's phone, as opposed to person-to-person chat. All bulk SMS is A2P.
- DND (Do Not Disturb)
- TRAI's registry letting consumers block promotional messages. Promotional SMS cannot reach DND numbers; transactional and OTP messages still can.
- TRAI
- The Telecom Regulatory Authority of India — the regulator whose rules (including the DLT framework and commercial-communication regulations) govern bulk messaging in India.
- SMPP
- Short Message Peer-to-Peer protocol — a telecom-grade protocol used for high-throughput SMS connections between platforms and operators, common for large enterprises and aggregators.
- Unicode SMS
- SMS encoded to support non-Latin scripts like Hindi, Odia or Tamil. Unicode messages fit 70 characters per part instead of 160, so regional-language texts split sooner.
- GSM-7 Encoding
- The default 7-bit SMS character set covering basic English letters, digits and common symbols, allowing 160 characters in a single message part.
- Message Parts (Concatenation)
- Long texts are split into multiple SMS parts (153 chars each for GSM-7, 67 for Unicode) and re-joined on the handset. You are billed per part, not per message.
- DLR (Delivery Report)
- Operator confirmation of what happened to each message — delivered, failed or pending — with timestamps. Real DLRs are how you verify a provider's delivery claims.
- WhatsApp Business API
- Meta's official interface letting businesses send WhatsApp messages at scale — template notifications, team inboxes and chatbots — via a solution provider. Distinct from the free WhatsApp Business app.
- Green Tick (Verified Badge)
- The verification badge on a WhatsApp business account showing Meta has confirmed the brand's authenticity. Granted at Meta's discretion to established businesses on the API.
- Template Message (WhatsApp)
- A pre-approved WhatsApp message format used to start conversations with customers (order updates, reminders, offers). Meta reviews templates for policy compliance before use.
- WhatsApp Chatbot
- Automated software that answers WhatsApp messages instantly — menus, FAQs, order capture, lead qualification — and hands over to a human agent when needed.
- RCS Business Messaging
- Rich Communication Services — the upgraded SMS inside Google Messages on Android, supporting verified brand identity, images, carousels and tappable buttons, with SMS fallback.
- IVR (Interactive Voice Response)
- A phone menu system (press 1 for sales, 2 for support) that greets callers, routes calls to the right team and records conversations — no hardware needed with cloud IVR.
- Missed Call Service
- A lead-capture method where customers give a free missed call to a published number; the call disconnects automatically and the caller's verified number is logged instantly.
- Voice Broadcast (OBD)
- Outbound dialing that plays a pre-recorded voice message to thousands of numbers in parallel — ideal for regional-language outreach — often with press-1 response capture.
- Opt-in / Consent
- A recipient's recorded permission to receive your messages, collected via forms, missed calls, QR codes or keywords. Consent is the legal foundation of compliant campaigns.
- Sender Reputation
- The trust score operators and platforms assign to your sending identity based on complaints, blocks and content quality. Poor reputation throttles delivery; good practice protects it.
- CPaaS
- Communications Platform as a Service — cloud APIs bundling SMS, WhatsApp, voice, RCS and email into one programmable platform, so businesses add messaging without telecom infrastructure.
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