In some cases, a very restrictive network and/or firewall can block access to services that are required for the streaming experience. If you encounter any issues of this nature, please add the entire UDP port range for streaming to your whitelist.

Also, include the following domains on port TCP 443:

ec2.*.amazonaws.com
.iot..amazonaws.com
.execute-api..amazonaws.com
.appsync-api..amazonaws.com
global.stun.twilio.com (UDP/TCP on port 3478 and TCP 443)

All of the above are secure https or websocket APIs, utilizing port 443.