A2P (application-to-person)

Messaging sent by software to a mobile user — notifications, OTPs, campaigns — over dedicated carrier connections, as opposed to person-to-person texts between two SIMs. All traffic through Ontech BulkSMS is A2P. See SMS gateway.

API key

A credential that identifies your account to the API. On Ontech BulkSMS a key has an Access ID and a Secret Key and only works from IP addresses you have whitelisted for it.

Bind

A persistent SMPP session between a client (ESME) and a message centre. Transmitter binds send, receiver binds receive, transceiver binds do both. See SMPP.

Blacklist

A per-account list of numbers that must never be messaged — opt-outs. The platform suppresses blacklisted numbers automatically on every send.

Bulk SMS

Sending one message to many recipients at once from a platform or API. See bulk SMS in Zambia.

Callback URL (webhook)

An address on your server that the platform posts delivery updates to, with retries on failure, so you receive reports without polling.

Campaign

A send to a contact group with tracking, optionally with two message variants and a split percentage for A/B testing.

Credit

The unit of billing. One standard message segment costs one credit; credits are bought by mobile money at volume rates.

Delivery report (DLR)

The mobile network's status for a specific message: delivered, failed or rejected (with queued and submitted as interim states). See delivery reports.

ESME

External Short Message Entity — the SMPP term for the client application that binds to a message centre.

GSM-7 / Unicode

The two SMS character encodings. GSM-7 (basic Latin text) allows 160 characters in one segment; Unicode (emoji, some symbols) allows 70. Longer messages are split into segments of 153 or 67 characters and billed per segment.

Long number

A full-length mobile number used to receive inbound messages, as an alternative to a short code.

Merge field

A placeholder in a template — for example a name or amount column — replaced per recipient with that person's value.

MO (mobile-originated)

A message sent by a person from a handset to the platform — a reply or a keyword. See two-way SMS.

MSISDN

A mobile number in international form without the plus sign, for example 260970000000; the format the API expects.

MT (mobile-terminated)

A message sent from the platform to a handset — every outbound SMS.

Opt-in / opt-out

A recipient's recorded consent to receive marketing messages, and their request to stop. Opt-outs go on the blacklist.

OTP (one-time password)

A short, time-limited code sent by SMS to verify a login, a transaction or a phone number. See OTP SMS.

P2A (person-to-application)

Inbound messaging from a person to a system — the same thing as MO traffic.

PDU

Protocol Data Unit — one SMPP operation on the wire, such as submit_sm (send) or deliver_sm (a receipt or inbound message).

Reseller

A partner who sells SMS to their own customers on the platform and earns commission on their top-ups. See the reseller programme.

Segment

One SMS part. Long messages are sent as several segments that the handset reassembles; each segment is billed.

Sender ID

The name or number shown as the sender. Alphanumeric sender IDs are up to 11 characters and are approved on an authorization letter.

Short code

A short number (Ontech's shared code is 388) that receives inbound messages; keywords route each message to the right account.

SMS API

An HTTP interface for sending and tracking SMS from software. See SMS API.

SMS gateway

The system between applications and mobile networks that routes, submits and reports on messages. See SMS gateway.

SMPP

Short Message Peer-to-Peer — the protocol for high-volume SMS over a persistent connection; Ontech BulkSMS runs an SMPP 3.4 server. See SMPP.

SMSC

Short Message Service Centre — the network element (or gateway) that stores and forwards SMS.

Template

A saved message with merge fields, reusable across sends and organised in template groups.

TPS (transactions per second)

Throughput. Each SMPP credential has a TPS limit; the HTTP management endpoints are limited to 60 requests per minute.

Transactional SMS

An event-triggered message to one person — a receipt, an OTP, a reminder. See transactional SMS.

Two-way SMS

Messaging in both directions: outbound sends plus inbound replies and keywords in an inbox. See two-way SMS.