Twilio signaling gateway unreachable when going through Cloud SWG

Products

• Cloud Secure Web Gateway - Cloud SWG

Issue/Introduction

Client applications using twilio reporting connectivity errors when accessing sites using Cloud SWG.

Issue appears with WSS Agents, Explicit and IPSEC access methods.

Can replicate using Twilio diagnostic tools at https://video-diagnostics.twilio.com/ - running diagnostics confirmed signaling gateway was unreachable.

Concerns exist about MFA authentication failing when accessing Applications via Cloud SWG.

Bypassing twilio.com from Cloud SWG fixes issue.

Environment

Cloud SWG.

All Access methods.

Cause

Certificate and TLS protocol dependencies built into client applications.

Resolution

Disable protocol detection for turn.twilio.com destination domain.

Additional Information

Twilio often used for MFA, and uses channels that use proprietary communication that is not SSL/HTTPS.