What each one is
SMPP (Short Message Peer-to-Peer) is a binary protocol over a persistent TCP session. A client binds to a server, submits messages as protocol units and receives delivery receipts on the same connection. It was designed for operators and aggregators exchanging thousands of messages per second. An HTTP API maps the same operations onto web requests: a POST creates a message, a GET reads its status, a webhook pushes the delivery receipt.
Side by side
- Connection. SMPP needs long-lived binds, keep-alives, window management and reconnect logic. HTTP is stateless; any client works.
- Encoding. In SMPP you set the data coding, split long messages and build concatenation headers yourself. An HTTP API detects the encoding, splits and numbers the parts, and tells you the segment count and the price.
- Delivery receipts. SMPP returns them as messages on the bind, which you parse and match. HTTP returns them as signed webhook events with your own reference attached.
- Retries. SMPP has no idempotency: a timeout leaves you guessing whether the message was accepted. An HTTP API with idempotency keys makes a retry safe.
- Operations. A bind is a server you run, monitor and whitelist. An HTTP call runs from anywhere, including serverless functions.
When SMPP is justified
When you are yourself an aggregator or a platform reselling traffic, when you sustain hundreds of messages per second around the clock, or when an existing system only speaks SMPP. For an application sending codes, notifications and campaigns, it adds cost and failure modes without adding delivery.
Getting volume out of HTTP
Volume over HTTP comes from batching, not from parallel single requests. One batch request carries up to 1,000 messages with per-message results; at 50 requests per second that is far more than most senders will ever need. Add pacing parameters so the platform spreads a large send, and receive results by webhook rather than by polling.
What SMSMeteor offers
A REST API: six endpoints, bearer keys, idempotency keys, batches, scheduling, signed webhooks and an OpenAPI description. SMPP is used on the carrier side and is not offered to accounts. If you need a bind, some providers in our comparisons offer one, and we say which.
Something unclear or out of date? Write to [email protected]; corrections are folded back into the guide and the update date changes.