HTTPS SMS gateways
An HTTPS SMS gateway sends text messages through your provider’s web API. Use it when your VoIP provider supports an HTTP SMS API instead of SIP SIMPLE.
These controls require an app build containing HTTPS SMS gateway support. An older installed or store version may not show them. SessionTalk Free requires Push and Business; SessionTalk paid includes the messaging controls. SessionCloud supports these settings for BYO PBX accounts.
Choose the gateway
Wait for any active call to end. Open Menu > Settings > Accounts, select the account and turn off Enabled before editing.
- SessionTalk: open Advanced SIP settings > Messaging, turn on Enable SMS, then choose SMS transport > HTTPS gateway.
- SessionCloud: open HTTPS SMS gateway, turn on Override provider SMS settings, then choose SMS transport > HTTPS gateway. This overrides outbound messaging only for this account. Turning the override off restores the provider’s messaging configuration.
Choose Gateway preset > Andrews & Arnold or Custom. Enter the gateway credentials, tap the checkmark to save, then re-enable the account. The gateway password is separate from the SIP account password. These BYO settings do not apply to Teams Hosted messaging.
Andrews & Arnold (A&A)
In the A&A control pages, configure the VoIP number’s outgoing SMS password. In the app, enter that number in full international format, without spaces, as SMS username, and enter its outgoing SMS password as SMS password. Do not substitute the SIP password. See the A&A SMS API documentation .
The preset fills these values automatically:
| Setting | Value |
|---|---|
| SMS gateway URL | https://sms.aa.net.uk/sms.cgi |
| Username parameter | username |
| Password parameter | password |
| Destination parameter | da |
| Message parameter | ud |
| Success response prefix | OK: |
The app submits a UTF-8, form-encoded HTTPS POST. The preset locks its URL and field mappings; choose Custom to edit them. Selecting a preset preserves the username and password you entered.
This messaging preset does not add a SIP account or register the number for calling. If A&A is absent from the standalone app’s provider directory, choose Generic SIP and use the SIP login details supplied by A&A. The calling password and SMS password remain separate. See Add a SIP account.
Custom gateway
Enter an HTTPS URL and the parameter names your provider uses for the username, password, destination and message. Each parameter name must be different. The app sends these four values as application/x-www-form-urlencoded data.
Set Success response prefix to the text your provider returns when it accepts a message. Leaving it empty accepts any successful HTTP 2xx response, except an explicit ERR: rejection. A successful HTTP status alone may be insufficient for providers that report errors in their response body.
Custom currently supports this four-field form API. JSON bodies, bearer tokens, custom headers, additional parameters and media uploads need a provider-specific integration. Do not enter a JSON API as a Custom gateway and expect it to work. URLs must not contain a username, password, query string or fragment.
The available presets are Andrews & Arnold and Custom. Telnyx and Twilio use the separate provider messaging service. Other suggested gateways, including sipgate and VoIP.ms, are not implemented presets.
Sending and message status
Open Messages > SMS, choose New SMS, select the account if prompted and enter the recipient’s full international number. Type the text and send it.
The app accepts up to 1,600 Unicode characters per submission. Your provider may apply a lower limit or divide the text into multiple chargeable SMS parts. A&A’s encoding and multipart rules are described in its SMS API documentation .
Sent means the gateway accepted the request; it does not confirm delivery to the recipient. If the connection times out or the result is uncertain, the message remains Delivery unconfirmed. Check the provider before sending again. The app does not automatically retry HTTPS submissions, because the provider may already have accepted them.
Incoming messages and MMS
The A&A and Custom presets support outbound text SMS only. They do not configure incoming SMS, delivery-report callbacks or MMS. The attachment button is hidden for these presets. Existing attachment history remains readable.
A&A offers separate incoming SMS forwarding options in its control pages; configuring an outgoing gateway in the app does not connect those incoming messages to the app.
For carrier MMS, use an MMS-enabled Telnyx number assigned through the provider messaging service. A Telnyx SIP login alone does not activate that service. SIP and chat attachments use a separate file-transfer service and are not carrier MMS.