Provides authentication through one-time passwords delivered via SMS text messages to the user's registered mobile number. This factor offers broad accessibility as it works with any mobile phone capable of receiving text messages.
📋 Prerequisites and Requirements
Requirement
Status
Description
Mobile Number
✅ Required
Valid mobile number must be registered during activation
Cellular Service
✅ Required
Device must have active SMS capability
SMS Reception
✅ Required
Phone must be able to receive text messages
REL-ID SMS Service
✅ System Provided
REL-ID platform handles SMS delivery
🔄 SMS OTP Authentication Flow
Number Verification: System validates user has registered mobile number
OTP Generation: 6-digit numeric code generated by system
SMS Transmission: Code sent via SMS to registered mobile number
Message Reception: User receives text message with authentication code
Code Entry: User manually enters 6-digit code on web portal
Server Validation: System validates entered code against generated code
Time Validation: Code must be used within expiration window
Authentication Result: Valid code allows authentication to proceed
⚙️ Configuration and Management
System Configuration
Setting
Location
Description
Impact
smsOtp
allowed.auth.factors
Enable/disable SMS OTP for authentication
Controls if SMS OTP available during login
smsOtp
allowed.reg.factors
Enable/disable SMS OTP registration
Controls if users can register mobile numbers
Mobile Number Registration Process
Number Entry: User provides mobile number during activation or in User Portal
Format Validation: System checks number format and validity
Test SMS: Verification code sent to provided number
Confirmation: User enters verification code to confirm number ownership
Storage: Verified mobile number stored for future authentication use
Mobile Number Update Process
Portal Access: User accesses security settings in User Portal
Re-authentication: Full authentication required before number change
New Number Entry: User provides replacement mobile number
Verification SMS: Test code sent to new number for verification
Confirmation: User enters verification code from new number
Update Complete: New number replaces old number in system
📊 SMS Delivery Characteristics
Characteristic
Details
Notes
Delivery Time
Usually 1-30 seconds
Can vary by carrier and network conditions
Code Length
6 digits
Standard numeric format
Expiration
Configurable (typically 5-10 minutes)
Code becomes invalid after expiration
Resend Capability
Available if initial SMS not received
Rate limiting may apply
International Support
Depends on SMS service configuration
May have additional costs or restrictions
🎯 Success and Failure Scenarios
✅ Success Scenarios
SMS Delivered: Text message successfully reaches user's mobile device
Code Entered Correctly: User enters exact 6-digit code from SMS
Within Time Limit: Code used before expiration period
Number Active: Mobile number is active and can receive messages
❌ Failure Scenarios
Failure Type
Cause
User Experience
Resolution Options
No Mobile Number
User hasn't registered mobile number
"No mobile number registered" error
Guide user to number registration process
SMS Not Delivered
Network issues, invalid number, or carrier blocking
No SMS received
Offer resend option or alternative authentication
Wrong Code
User entered incorrect digits
"Invalid code" error message
Allow retry with same code
Expired Code
Code used after expiration time
"Code expired" error
Generate and send new code
Carrier Issues
SMS service problems or delays
Delayed or missing SMS
Provide alternative authentication methods
Resend Functionality
User Option: "Resend SMS" link available if code not received
Rate Limiting: Prevents abuse with time delays between resend attempts
Alternative Methods: System may suggest other authentication factors if SMS consistently fails
Troubleshooting: Users guided to check phone reception and SMS blocking settings
Mobile Number Management
Registration Required: Number must be registered before SMS OTP can be used
Verification Process: All numbers verified through test SMS during registration
Update Capability: Users can change numbers through User Portal
Security: Number changes require re-authentication to prevent unauthorised modifications
