VoiceThread Docs / Troubleshooting / Network requirements

If you are working on a local area network, there are some network settings that will allow VoiceThread to function quickly and reliably. Please pass this information along to your local network administrator so he or she can make any necessary changes.

The following URLs must be open on your local network:

If you have a firewall, you should allow access to media.voicethread.com on port 1935. If you are using a proxy server, or if your firewall filters based on packet content, you may need to do more advanced configuration. To see if you’ve got it right, you can take the test on this page: http://voicethread.com/test/media.swf. Please note that port 1935 is RTMP (a media streaming protocol) and not HTTP; this means that your proxy must pass a direct connection through. If your proxy attempts to treat all traffic as HTTP, then RTMP over port 1935 may fail.

Adequate bandwidth for the number of local users

Computer labs with many users simultaneously recording commentary can strain local bandwidth resources, so some trial and error might be necessary to find the maximum number of simultaneous users that your network connection will allow. If you are using an asymmetric network connection (such as most cable modem and DSL connections), you will find that upstream bandwidth may be an issue even though there is plenty of downstream bandwidth. This is because uploading and recording use upstream bandwidth, and connections commonly have 10-20 times as much downstream bandwidth as upstream.

If you wish to verify your connection speed, please use a speed testing service such as http://speedtest.net/. Pay particular attention to the upstream speed shown. This is the limiting factor for commenting and uploading.

Proxies for full VoiceThread functionality

Your proxy must allow actual plain TCP connections (not just HTTP) on port 1935, as well as HTTP on port 80 and HTTPS on port 443 to the VoiceThread servers, as defined above.


You must accept e-mail from the voicethread.com and amazonses.com domains. Please note that VoiceThread e-mail is easy to verify, as we have implemented a number of e-mail authentication technologies (DKIM and SPF).

If you are using a Barracuda Networks anti-spam appliance, please make sure to specifically whitelist voicethread.com; the Barracuda device may otherwise be prone to false positives.

If you are using the Lightspeed Systems anti-spam solution, we strongly recommend that you whitelist voicethread.com. While we will attempt to catch any verification attempts, this may result in substantial delays in invitations and notifications.