Set up an SMS Channel for Bandwidth

This topic describes how to set up a Bandwidth SMS channel on Yeastar P-Series Cloud Edition, so that agents in your business can receive and reply to SMS messages from customers on their Linkus UC Clients.


The Yeastar PBX should meet the following requirements:

  • Firmware: Version or later
  • Plan: Enterprise Plan (EP) or Ultimate Plan (UP)
  • Domain Name: Due to the limitation of the third-party platform, the domain name must NOT contain underscore character(s), otherwise the messaging channel will encounter authentication failure, or will fail to receive messages.
  • Domain Certificate: A valid domain certificate is installed.
    Note: If the root domain of your Cloud PBX is NOT the standard Yeastar-provided domains (,, or, you NEED to install a valid domain certificate for the PBX first, otherwise the messaging channel will encounter authentication failure, or will fail to receive messages.

Supported message types and limits

Supported message types
The Bandwidth SMS channel supports text messages and multimedia messages (MMS), where the supported MMS file types are determined by Bandwidth. For more information, see Bandwidth supported MMS file types.
Important: When sending multimedia messages (such as images), the SMS service provider downloads the files from a link provided by the PBX. Therefore, if you have set Allowed Country/Region IP Access Protection rule, make sure that you have allowed the IP access from the country where the SMS service provider is located, otherwise the file transmission would fail.
  • File size: Max. 100 MB
  • File retention period: 24 hours



Step 1. Obtain a Webhook URL on PBX

Obtain a Webhook URL from PBX web portal first, which is required when you configure a number for SMS on Bandwidth.

  1. Log in to PBX web portal, go to Messaging > Messaging Channel.
  2. Click Add, and select SMS.
  3. In the ITSP drop-down list, select Bandwidth.
    A Webhook URL for Bandwidth is generated and displayed in the Webhook URL field.
    Important: The URL will change once you leave the current page, please make sure you use the latest Webhook URL for the configuration on the service provider's customer portal.

  4. Note down the Webhook URL.

Step 2. Configure a number for SMS on Bandwidth

Important: According to US legislation (A2P 10DLC SMS), 10DLC (10-digit Long Code) phone numbers that are used for A2P (Application-to-Person) messaging MUST be registered, otherwise SMS messages sent to US numbers from unregistered 10DLC numbers will be blocked.

If your business needs to communicates with US-based customers, you should confirm the registration requirements with the SMS service provider and complete the phone number registration to avoid disruption in message delivery.

Log in to Bandwidth portal, and complete the followings:
  1. Create an application using a sub-account and configure the callback with PBX's Webhook URL.

  2. On the details page of the new application, associate the application with your location.

  3. Enable HTTP SMS and MMS messaging for your location and the associated application.

  4. Search the number that you want to use for SMS and associate it with your sub-account.

  5. Note down the Application ID and Account ID for the integration with PBX.

Step 3. Create and configure an SMS channel on PBX

Create an SMS channel on PBX, and configure the channel with the authentication information and number obtained from Bandwidth.

  1. Log in to PBX web portal, go to Messaging > Messaging Channel.
  2. Click Add, and select SMS.
  3. In the Authentication tab, enter the authentication information of Bandwidth.

  4. In the Messaging Settings tab, configure the channel.
    1. In the Message Sending Rate drop-down list, specify the number of messages that PBX can send per second.
      • If the number of messages to send exceeds the set value, PBX will arrange the messages in queue and send them at the sending rate.
      • If the sending rate set in PBX exceeds the limit set by the SMS service provider, it may result in message delivery failures. Contact your SMS service provider to confirm the sending rate limit of your account and increase the limit as needed.
    2. Optional: If you want the system to automatically close the sessions that have been inactive for a specific period of time, select the checkbox of Close Session Automatically, then set the timeout in the Session Timeout (Days) field.

    3. In the Number section, click Add to add a message routing rule.

      • Number: Enter the purchased number in E.164 format ([+][country code][phone number]). For example, +14102161183.
      • Destination for Inbound Messaging: Specify the destination of inbound messages from the number.
        Option Description
        Extension If selected, choose an extension from the Extension drop-down list.

        Only the extension user can receive inbound messages from the number.

        Message Queue If selected, choose a queue from the Message Queue drop-down list.

        All the agents in the selected message queue can receive inbound message(s) of new sessions in the queue. However, only the user who picks up a session will be able to receive and respond to the follow-up inbound messages in the session.

      • Extensions allowed to create messaging sessions: Select the extensions that are allowed to initiate a messaging session with customers.
    4. Click Save.
  5. Click Save.


  • A messaging channel is created successfully. You can see the channel displayed in the Messaging Channel list with Status showing .

  • PBX automatically tracks and records the number of messages sent and received on the channel, where the Total column indicates the total number of sent messages, including both successfully sent messages and failed ones.
    • For sent messages, PBX only tracks the number of the messages sent from agents' Linkus UC Clients. If you want to calculate the actual cost of sent messages, consult with the SMS service provider for the precise number of messages transmitted, as long text messages (longer than 160 characters) are automatically split into segments and then re-assembled when they are received, increasing the number of sent messages.
    • You can filter the statistics by a time period using the time filter.

What to do next

Send text messages to the phone number and see if the specified agent can receive messages on his or her Linkus UC Client.