---
title: "SMPP"
description: "SMPP (Short Message Peer-to-Peer) is an open binary protocol over TCP that applications (ESMEs) and SMS providers use to exchange SMS with an SMSC. Version 3.4 is the most widely deployed."
canonical: "https://omnichannels.ai/glossary/smpp/"
language: "en"
updated: "2026-10-10"
publisher: "BroadNet Technologies"
brand: "OmniChannels.ai"
---

# SMPP

Canonical: https://omnichannels.ai/glossary/smpp/
Language: en
Publisher: OmniChannels.ai by BroadNet Technologies

**Definition:** SMPP (Short Message Peer-to-Peer) is an open binary protocol over TCP that applications (ESMEs) and SMS providers use to exchange SMS with an SMSC. Version 3.4 is the most widely deployed.

An SMPP session starts with a bind (transmitter, receiver or transceiver). The client then sends messages with submit_sm and receives inbound messages and delivery receipts as deliver_sm. enquire_link keeps the session alive and unbind closes it.

Every PDU has a 16-octet header: command_length, command_id, command_status and sequence_number. Responses echo the sequence number, so many requests can be in flight at once (windowing), which is what makes SMPP efficient for high volume.

SMPP suits aggregators, resellers and enterprises sending large volumes, or those with existing SMS software. For most application developers an HTTP SMS API is simpler.

The base protocol has no encryption, so connections should run over TLS or a VPN, and IP allow-listing is common.

OmniChannels.ai provides SMPP 3.4 over TLS with binds provisioned per account.

## Example

```
bind_transceiver → bind_transceiver_resp → submit_sm → submit_sm_resp (message_id) → deliver_sm (receipt) → deliver_sm_resp
```

## Sources

- [SMPP Protocol Specification v3.4 (Issue 1.2) — SMPP.org](https://smpp.org/SMPP_v3_4_Issue1_2.pdf)