TwentyThree employs global infrastructure to connect webinar hosts and speakers, and the product uses real-time communication protocols on the browser for live video, audio and messages. In most cases, you won't need to make any network changes to connect, but in some settings network communications may be blocked by the network administrator — these blocks may need to be reconfigured to allow webinar hosts and speakers to connect correctly.

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

If you have problems connecting to webinars on TwentyThree:

• Make sure you’re not connected to the internet over a VPN connection. VPN connections are often subject to network blocks, so you may find that joining a webinar through a VPN will cause connectivity issues.
• Reload the app: Refreshing the webinar room is safe, and you will be automatically reconnected to the room. This can help to reconnect your devices and network in the room. 
• Restart Chrome: When applying new settings in the browser or adding new devices to the webinar, you might need to restart your Chrome browser in order to activate your new settings.
• Make sure your laptop is plugged in to power. Video broadcasts use extensive resources on the computer, and a laptop works differently when it’s plugged into the wall. So if you’re seeing poor video quality, slow-loading apps or connection problems from the webinar room, adding direct power often offers a huge improvement.
• Run the network test in TwentyThree: The network test in TwentyThree can quickly help you determine what could be affecting your webinar connectivity. Refer to the below guide on how to use and read the test. 
• Reboot the computer: Some settings, updates and even new devices will require you to restart your computer in order to be correctly applied. It is a good idea to make sure to update your browser and software in advance of the webinar, just to make sure that you have the latest version and correct settings. 

Using and Reading the TwentyThree Connection Test

We recommend you take the full TwentyThree network test before each webinar. To create accurate results, use the same network and device set-up as you will for your webinar. You can find the network test from your webinar’s Overview page towards the bottom of the right-hand sidebar. Click on “Take the full test,” and the test will open in a new browser tab. When you click “Start the test,” your browser, microphone, camera, network, connectivity and throughput will be tested. 

In order to test your browser and microphone, you'll need to make sure to give access to those devices in the browser. During the microphone test, you will need to ensure that audio is actively being transmitted through the microphone, so try talking or otherwise making a sound. 

Once the test is complete, you'll see which aspects of the test have been passed — indicated by a green checkmark — and the ones with warnings — indicated with a red warning triangle. Here is how to troubleshoot these errors: 

Browser: Make sure you are using a Chrome browser. If you are already using Google Chrome, try updating your browser to the latest version. 

Microphone: Make sure your microphone is not muted or turned off. Make sure that you are actively talking or otherwise making some noise while the test runs. If you're using an external microphone, you might also want to try to unplug and plug it in again while making sure that Chrome has the correct device selected. 

Camera: Make sure that your camera is on and connected. If you're using an external camera, you might want to unplug and plug it in again and make sure that Chrome has the correct device selected. 

Network, Connectivity and Throughput: These network tests are to make sure that your browser can connect to the webinar infrastructure and that you have sufficient bandwidth to run a high-quality webinar. If you see any issue during the test, refer to the guide on network configuration below.

Network Requirements

In order to ensure quality for hosts and speakers alike, it may be required to have some network ports opened on your corporate network. If you have any connection issues for hosts or speakers we recommend that you check that the guidelines below have been followed

The product uses standard HTTPS/SSL/TLS communication for loading the application and for data to flow with the API. 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.

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 and Reading the Twilio Connection Test

If you experience issues with your connection during webinars and want a deeper analysis of your network connection you can take the Twilio network test. The test is more robust than the TwentyThree one and can help provide further insights on which aspects of your connection might be the cause. 

To take the test, go to http://networktest.twilio.com/. The test will automatically start once the page loads, and like with the TwentyThree test, you will need to provide the page access to your microphone and camera. During the microphone test, you will be asked to record a message, during which you need to actively talk or otherwise make a sound to be recorded for the test. 

Once the test is complete, you will see which aspects of the test were passed and which were failed on the left-hand side along with a log of further information on the different test aspects on the right side.