Troubleshoot SIP and WEBEX Cloud meeting interoperablity.

Situation We are aiming to dial into a Webex meeting from a SIP device. We have a self-hosted Asterisk server that is connected to our video conference application We are registering this Asterisk SIP account with our video conference application and Dialing into Webex cloud meeting and various telepresence hardware such as CISCO Telepresence, Polycom etc. Complication 1. We are able to successfully connect to telepresence hardware with no problem whatsoever. - PASS 2. We are NOT able to connect to webex cloud meetings (both personal account and organization account). ​We are getting we are getting this 408 request timeout error. - FAIL Screenshots attached for reference Requirement 1. We require you to work with us and help troubleshoot this issue.