SIP Client Registration and Call Failure After Creating a Secondary API Secret

Symptom

SIP client registration and outbound call initiation suddenly fail with authentication errors.

During call initiation, the SIP INVITE request receives a 407 Proxy Authentication Required challenge. The client responds with a valid Digest authentication response, but the authentication still fails.

During SIP REGISTER attempts, the server returns 401 Unauthorized, preventing successful registration.

These errors begin after creating a secondary API secret.

Applies To

• Voice
• SIP
• SIP trunking

Resolution

If the issues started after creating a secondary API secret, update your SIP client configuration to use the newly created API secret.

After updating the credentials, restart your SIP clients to trigger a new SIP REGISTER request.

Place a test call to confirm that 401 Unauthorized and 407 Proxy Authentication Required errors no longer occur.

Recommendation:
For SIP calls, use SIP trunk–based authentication (SIP username/password) generated via the SIP Dashboard instead of API key/secret authentication. 

Cause

When a secondary API secret is created, SIP authentication only accepts the newly created (secondary) API secret.

The original API secret may fail for SIP registration and call authentication.

This limitation applies only to SIP-based authentication. For non-SIP API requests, both API secrets continue to function as expected.