SMS Gateway: What Is It and How Does It Work?

Dikran Seferian
Dikran SeferianContent Writer

Published: Feb 3, 2020

SMS Gateway

Whether you're sending appointment reminders, marketing promotions, or important alerts, using an SMS gateway can help you reach your target audience efficiently. And with the prevalence of texting, it's no surprise that businesses have turned to this medium to communicate with their customers. But with so many options available, choosing the right one for your needs can be overwhelming. 

We’ve created a foolproof guide, including benefits and how to choose the right one for your business, so you can communicate with your customers with ease. Let's dive in and discover how it can revolutionize the way you communicate with your customers and stakeholders.

What is SMS Gateway? 

An SMS gateway is a system that lets people send and receive text messages from a computer to a Short Message Service Center (SMPP). The latter then transmits messages to the mobile device on its network. If programmed appropriately, this system can convert a message into multiple formats for cross-platform compatibility. An SMS gateway is handy for organizations that often send bulk SMS and require a specialized gateway to manage all incoming and outgoing messages.

What is an SMS Gateway List?

A "SMS gateway list" refers to a compilation of different SMS gateway providers or services that offer the infrastructure to send SMS messages programmatically. These lists may include information such as the gateway provider's name, API documentation, pricing details, supported countries, and other relevant information.


How Do SMS Gateways Work?

At its core, a gateway is a bridge between mobile networks and the internet, enabling two-way communication between brands and their customers. When a company texts a customer, the message goes from the business' computer or server to the customer portal gateway. Here is a step-by-step explanation of how it works:

  1. The business composes a text message on its computer or server and sends it to the gateway, which converts it into a format that can be sent over the mobile network

  2. It then forwards the message to the mobile network of the recipient's phone

  3. The mobile network delivers the gateway text to the recipient's phone

  4. When the recipient responds to the message, the mobile network sends the response back to the gateway, which turns it into a format that can be received by the business's computer or server

  5. The gateway then forwards the response to the business's computer or server

  6. The company receives the response and can then take action accordingly

How Does SMS Gateway Work

How Does a Gateway Differ from an SMS API?

While a gateway is similar to an SMS API, the two are not the same. A messaging gateway refers to a service that allows for sending and receiving message transmissions to or from a network. In many cases, this involves converting emails to text messages and vice versa. A text message gateway comes in handy for bulk texting, providing SMS software services to mobile users, and integrating messaging functionalities into other applications. 

On the other hand, an SMS API is a set of protocols that enable various applications to interact with an SMS messaging gateway. It’s how developers connect their software to the gateway in a structured manner. The API defines how the various components of the software are supposed to interface with each other. This allows the system to send and receive text messages via the gateway. Although APIs and gateways work together, they each serve a different role in the process of exchanging messages. 


What is the Difference Between an SMS Server and SMS Gateway?

The terms "SMS server" and "SMS gateway" are often used interchangeably, but they refer to different components in the context of sending and receiving text messages.

An SMS server is a software application or a hardware device that is responsible for handling the storage, processing, and management of text messages. It typically runs on a server or a computer system and provides various functionalities related to text communication. SMS servers can handle tasks such as message queuing, message routing, conversion, and integration with other systems or applications.

On the other hand, an SMS gateway is a communication infrastructure that acts as a bridge between different telecommunications networks, enabling the transmission of text messages between these networks. It serves as a relay for SMS traffic, facilitating the exchange of messages between different devices or systems.

SMS gateways are usually connected to mobile network operators (MNOs) or service providers, and they handle tasks such as message routing, protocol conversion (e.g., converting between SMPP, HTTP, or other protocols), and delivery of messages to the intended recipients.

In some cases, a single system may combine the functionalities of both an SMS server and an SMS gateway, blurring the distinction between the two terms.

How is SMS Gateway Used?

Using a bulk SMS gateway provider, companies and organizations can only send text messages to thousands of customers at the same time. Bulk SMS gateways provide prompt communication with customers, whether it’s flash sales, discounts, surveys, or any other SMS marketing-related information. What’s more enticing is that text messaging offers a very affordable way to advertise products and offerings.

Companies can create greater brand awareness, and it's especially useful for bridging the gap in telecommunications. Essentially, it builds a bridge between different protocols, allowing communication to flow seamlessly by translating the messages according to the communication protocols. 

Multiple software options allow for messaging gateways. Some require the purchase of a license beforehand; others are free open-source options. An online SMS gateway provider may also support HTML/HTTPS interfaces, which are arguably more comfortable to use compared to ones under SMSC. However, an HTML/HTTP API might not have as many SMS-specific features as an SMSC protocol.


What is an SMS Gateway API?

An SMS Gateway API is an application programming interface that allows software applications to interact with a gateway provider to send text messages. This API enables developers to integrate text messaging functionality into their applications, websites, or software platforms, allowing companies to engage in business text messaging. 

The API works by providing a set of protocols and procedures that enable software applications to connect to a gateway provider's platform via the internet. It allows developers to create custom applications that can send text messages, query message status, and perform other text-related tasks.

Text Message API Service Pricing

Dexatel employs a pay-as-you-go approach that charges you per sent message. This is the most affordable SMS gateway pricing model, and the service costs are free of setup, monthly, or any other fees.

Using the API can provide many benefits, such as enabling businesses to automate their text communications, increase customer engagement, and streamline their communication processes. For example, businesses can use the API to send personalized messages, automate appointment reminders, or send promotional offers to customers.

This is widely used in various industries, including banking, eCommerce, healthcare, and logistics. By integrating text communication functionality into their applications, businesses can provide their customers with a more convenient and personalized mobile communication experience.

Sending SMS Messages from Email Using Gateways

The process of sending emails as SMS is relatively simple, and it involves composing an email and sending it to the gateway, which will then convert it into a text message and deliver it to the intended recipient. In other words, you can send an email to a specific email address provided by the service, and the email content will be converted into a text and delivered to the recipient's mobile phone number. This can be especially useful for companies that need to send bulk text messages to their customers or stakeholders. 

Are There Any Open-Source Gateways? 

There are many free open-source SMS gateway providers available that hold no commercial license. They provide businesses with greater control over their messaging infrastructure. Companies and organizations can customize the software to meet their specific requirements and integrate it with their existing applications or software systems.


Top SMS Gateway Providers You Need to Know About

Here are some of the best providers and top open-source services you can use for your business messaging needs:


Kannel supports a wide range of protocols. These include SMPP, UCP, and HTTP. It is written in the C programming language and is widely used in the telecom industry. Kannel offers scalability and can support thousands of text messages per second. It is common among service providers, mobile operators, as well as businesses using it for marketing purposes. 

Ozeki NG SMS Gateway

Ozeki NG is supports a range of messaging protocols and APIs, including HTTP, XML, and SMPP interfaces. It also provides delivery reports and supports two-way messaging, in addition to featuring a user-friendly interface that enables you to send and receive text messages in addition to managing contacts and creating templates. Ozeki is written in the .NET language and runs on Windows-based systems. 


Gammu is supports a wide range of mobile phones and modems. It can be used to send and receive messages, as well as manage contacts and text message templates. Installing and configuring it is easy, and it provides access to a comprehensive documentation library. Gammu is written in C++ and features a command-line interface that you can integrate with other applications via APIs.