Understanding SMS messaging

Short Message Service (SMS) is a text messaging service that uses standardized communication protocols to send short text messages to or between devices. These messages are transmitted via cellular networks.

Communications APIs, like Vonage’s Messages API, let you programmatically send SMS messages by making an HTTP request to an API endpoint. The message is then passed downstream to the cellular network for delivery to the recipient’s device.

The Messages API and the SMS API

There are currently two Vonage APIs with which you can send SMS Messages:

• The Messages API
• The SMS API

There are some differences between the two APIs which you may want to consider when deciding which one to use.

Messages API

• The Messages API is a multi-channel messaging API which supports other messaging channels as well as SMS
• This includes other network-based channels such as MMS and RCS, as well as OTT channels such as WhatsApp and Facebook Messenger
• All the channels use the same endpoint and the same basic structure for request payloads, so multiple channels can be used via a single integration
• The Messages API will continue to be enhanced with new features and support for network-based and OTT channels
• The Messages API provides a Messages Status webhook which supports the following statuses:
  • submitted
  • delivered
  • rejected
  • undeliverable

SMS API

• The SMS API is suitable for high throughput (e.g. > 500 messages/second) use cases (increased throughput levels are only available on request)
• The SMS API provides HIPAA compliance
• The SMS API provides Delivery Receipts for individual messages segments (where a lengthy message has been split into multiple parts for delivery).
• The SMS API Delivery Receipts support the following statuses:
  • accepted
  • delivered
  • buffered
  • expired
  • failed
  • rejected
  • unknown

Getting started with SMS on Messages API

There are a few things to set up in order to get started with sending SMS with the Messages API.

Account settings

In your Developer Dashboard account, on the Settings page, you need to set the SMS settings to ‘Messages API’. This is to ensure that any webhooks related to SMS messages are received in the expected format for the API that you select.

Create an Application

You will need to create a Vonage Application in order to generate credentials for authentication and to contain various settings related to usage of the API.

You can read more about creating a Vonage Application in this document.

Configure Webhooks

The Vonage Application is also where you configure your webhooks.

The Messages API provides webhooks for Inbound messages and also for Message Status.

You can read more about configuring your webhooks in this document.

Guides

The following guide documents provide further details about some specific aspects of sending SMS messages:

• Concatenation and Encoding
• Sender Identity
• Country Specific Features