Messaging
SMPP vs HTTP API: which SMS architecture for your high volumes?
When your platform sends a few hundred SMS a day, a standard HTTP API is perfectly sufficient. But when you move to hundreds of thousands of messages a month · marketing campaigns, transactional alerts, peak-time OTPs · the limits appear quickly.
What an HTTP API cannot do
An HTTP API is stateless: each request opens a new TCP connection, negotiates TLS and waits for a response. This cycle takes time. At 50,000 simultaneous messages, your server is overwhelmed by connections and timeouts multiply. What's more, delivery receipts (DLRs) arrive asynchronously and must be polled or received via webhook: this adds complexity to the architecture.
SMPP: a persistent connection
The SMPP (Short Message Peer-to-Peer) protocol works differently: a TCP connection is established once and kept alive. Messages are sent through this tunnel with no re-establishment overhead. DLRs come back over the same connection. Throughput is unmatched and latency is minimal.
Why Jasmin
UrbanSMPP is built on Jasmin, the leading open-source SMPP engine. Jasmin natively handles routing, per-route throttling, DLRs and high availability. Our interface layer adds a visual dashboard to manage your connections, routes and campaigns without touching the low-level configuration.
Rule of thumb: if you send fewer than 50,000 SMS a month, an HTTP API is enough. Beyond that, or if you have latency constraints on your OTPs, UrbanSMPP guarantees the throughput and reliability you need.