TwentyThree employs a global infrastructure to connect webinar hosts and speakers using real-time communication protocols within the browser for live video, audio, and messaging. In most cases, no network adjustments are needed. However, in some settings, network communications may be blocked by the network administrator, requiring reconfiguration to allow proper webinar connections.

Important Note

This article covers network settings required for webinar hosts and speakers. It does not apply to viewing videos, webinars, or live streams. For optimizing your network for watching webinars and live streams, please refer to this article.

Troubleshooting Webinar Connectivity Issues

If you experience issues connecting to webinars on TwentyThree, try the following steps:

• Avoid VPN connections: VPNs are commonly used to enhance security and privacy, but they can also introduce network restrictions that interfere with webinar connections. If you are experiencing issues, disconnect from your VPN and try joining again.
• Refresh the page: Reloading the webinar room is safe and will automatically reconnect your devices and network. This simple action can resolve temporary connection issues and restore functionality.
• Restart Chrome: Changes to browser settings or newly connected devices might not be recognized until Chrome is restarted. If you experience problems after adjusting settings or connecting peripherals like microphones or cameras, restart your browser.
• Plug in your laptop: Running video broadcasts requires significant system resources. When on battery power, a laptop may limit performance to conserve energy, leading to lower video quality, lagging applications, or connectivity issues. Plugging in your laptop ensures full power availability and improves performance.
• Reboot the computer: Some software updates, newly installed devices, or network setting changes require a complete system restart to take effect. To prevent issues, update your browser and software in advance and reboot before your webinar.

Network Requirements

For optimal performance, certain network ports must be open on corporate networks. TwentyThree uses standard HTTPS/SSL/TLS communication for loading applications and API data. Additionally, two protocols improve connection quality:

We also use two additional protocols to increase the quality of connection and videos: 

• WebSockets (WSS) are used for real-time communication between the browser and our servers. This connection generally runs on TCP port 433, so ensure that any firewall responsible for this traffic is capable of delivering WSS traffic, or that the domains listed below are appropriately whitelisted.
• User Datagram Protocol (UDP) is the preferred protocol to carry video stream to provide additional resiliency and quality. The application can be deployed with UDC blocked, but we strongly recommend opened up ports listed below.

Required Domains for WebSockets

The following domains must be opened for WebSockets:

• wss://*.twilio.com on port 443.
• wss://*.firebaseio.com on port 443.

The following IP ranges are used for media signaling and global video realtime relays. The ranges must be opened for TCP on port 80, 443, 3478 and 5349. Additionally, the ranges should be opened for UDP/SRTP/SRTCP on port 3478 and ports 10,000–60,000 to ensure the highest possible quality:

• 13.210.2.128 – 13.210.2.159
• 54.252.254.64 – 54.252.254.127
• 3.25.42.128 – 3.25.42.255
• 18.231.105.32 – 18.231.105.63
• 177.71.206.192 – 177.71.206.255
• 18.230.125.0 – 18.230.125.127
• 52.59.186.0 – 52.59.186.31
• 18.195.48.224 – 18.195.48.255
• 18.156.18.128 – 18.156.18.255
• 52.215.253.0 – 52.215.253.63
• 54.171.127.192 – 54.171.127.255
• 52.215.127.0 – 52.215.127.255
• 3.249.63.128 – 3.249.63.255
• 52.66.193.96 – 52.66.193.127
• 52.66.194.0 – 52.66.194.63
• 3.7.35.128 – 3.7.35.255
• 13.115.244.0 – 13.115.244.31
• 54.65.63.192 – 54.65.63.255
• 18.180.220.128 – 18.180.220.255
• 13.229.255.0 – 13.229.255.31
• 54.169.127.128 – 54.169.127.191
• 18.141.157.128 – 18.141.157.255
• 34.203.254.0 – 34.203.254.255
• 54.172.60.0 – 54.172.61.255
• 34.203.250.0 – 34.203.251.255
• 3.235.111.128 – 3.235.111.255
• 34.216.110.128 – 34.216.110.159
• 54.244.51.0 – 54.244.51.255
• 44.234.69.0 – 44.234.69.127

Furthermore, all video and streamed content from TwentyThree is delivered from the following domains which should be whitelisted:

• delivery.twentythree.com

• *.delivery.twentythree.com

Using the Twilio Connection Test

For a deeper network analysis, use the Twilio network test:

1. Visit Twilio Network Test.
2. Allow access to your microphone and camera.
3. Complete the microphone test by recording a message.
4. Review test results, identifying passed and failed aspects.

By ensuring these network requirements are met, webinar hosts and speakers can achieve optimal performance and connection stability in TwentyThree webinars.