If you are building an A2P SMS platform, you’ll often see two options for connecting applications and partners: SMPP and HTTP API. Both can deliver messages, but they are designed for very different use cases.
What Is SMPP?
SMPP (Short Message Peer-to-Peer) is a binary protocol originally designed for telecom operators. It runs over a persistent TCP connection and is optimized for high throughput and low latency SMS delivery.
Key characteristics:
- Persistent bind (connection) with enquire_link keep-alives
- Supports high TPS (hundreds or thousands of messages per second)
- Detailed delivery reports and error codes
- More complex to implement but very powerful
What Is HTTP API?
An HTTP SMS API exposes SMS sending via simple HTTPS endpoints. Your application makes requests with parameters like destination number and message text, and gets a synchronous response.
Key characteristics:
- Easy to integrate with any web or mobile backend
- No persistent connection; each request is independent
- Lower throughput compared to SMPP, but enough for many use cases
- DLRs often pushed via webhooks or retrieved via polling
Side-by-Side Comparison
| Feature | SMPP | HTTP API |
|---|---|---|
| Typical Use | Operators, aggregators, high-volume platforms | Web applications, SaaS, small/medium businesses |
| Throughput | Very high (1000+ SMS/sec possible) | Moderate (depends on concurrency & rate limiting) |
| Connection Type | Persistent TCP session (bind) | Stateless HTTP(S) requests |
| Complexity | High – needs SMPP library and tuning | Low – simple REST/JSON or query string |
| DLR Handling | Native SMPP deliver_sm PDUs | Webhooks/callbacks or separate query API |
| Best for | Gateways, carriers, wholesale resellers | Web apps: OTP, notifications, marketing |
When to Use HTTP API
HTTP API is usually the right choice if:
- You are a developer building a web or mobile application
- You send moderate volumes of SMS (e.g. OTPs, alerts, small campaigns)
- You want fast integration without telecom-level complexity
- You prefer JSON/REST and standard HTTP tooling
Most OnnetBD IT customers start with HTTP/REST APIs for OnSMS and only move to SMPP when they scale into millions of messages.
When to Use SMPP
SMPP is the better option when:
- You are an SMS aggregator or operator with very high throughput
- You need tight control over window size, rate limiting and queuing
- You connect directly to mobile operators or large partners
- You need detailed per-message error codes and advanced features
Implementing SMPP requires more effort: you must manage reconnections, enquire_link, PDU parsing, and scenarios such as throttling and temporary route failures.
Combining SMPP and HTTP in One Platform
Many professional SMS platforms expose both interfaces:
- SMPP for wholesale and telecom-level customers
- HTTP/REST for developers, e-commerce, and SaaS integrations
OnnetBD IT can design such a platform for you, including routing logic, DLR management, reporting and billing layers on top of open-source components like Jasmin SMS Gateway.
Which One Should You Choose?
- If you want simple integration for your app → start with HTTP API.
- If you are a gateway or telecom partner → you will likely need SMPP.
- If you serve different customer types → offer both via one backbone platform.
👉 Need help designing an SMPP/HTTP SMS architecture or Jasmin-based platform? Talk to OnnetBD IT for a full technical and business plan.