Coviu Firewall and Proxy Settings

This article outlines configuration changes that may be required on your corporate network to allow Coviu to work. Typically, your IT Network Administrator would undertake these activities.

Last updated: Nov 2021

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On this page:

  1. Test as you go
  2. Issue 1: You cannot open the website
  3. Issue 2: You cannot connect into a room
  4. Issue 3: Your client or patient cannot enter into your room
  5. More support options

For Network Administrators: Test as you go!

Anyone can use the below pre-call test to see if they are ready to use Coviu however Network Administrators can use the pre-call test to see if Coviu will work on their corporate network. If the test shows failures on UDP, TCP or STUN, then use the below scenarios to troubleshoot and make changes where necessary.

TIP: Network Administrators can use our pre-call test to test as they go.

Issue 1: You cannot get to

If you are able to view other websites e.g. without issue, then read on. If you cannot view any other websites, then you may wish to consult your IT Support staff.

Analysis: your network has a very tight Web proxy which filters out Websites it does not know. 

Remedy: ask your IT Network Administrator to allow access to the following domains: 

  • (required)
  • (required - provides static resources)
  • (required - provides application images)
  • (required - provides the video calling rooms)
  • (required - to load special in-call functionality)
  • (advisable - we use this to debug any call issues you're reporting)
  • (advised - this provides the right fonts)
  • (optional  - this allows us to capture application issues)
  • (optional - this allows us to capture usage analytics)
  • Make sure the Web proxy can do a Websocket upgrade on and port 443.

Issue 2: When trying to connect to another person, they never appear in your Coviu video room

Analysis: you are not connecting to the Coviu signalling server, which is connecting up the endpoints to each other via Websockets.

Remedy: ask your network administrators to open up the following ports.

These ports are necessary so we get to our ICE/STUN servers to deal with the NAT:

  • tcp/19302
  • udp/19302
  • tcp/3478
  • udp/3478

Make sure you also have these accessible in your proxy server:

  • (required - to reach ICE/STUN servers)
  • * (required - to reach signalling servers)
  • * (required - to reach signalling servers)
  • * (required - to reach our backup TURN servers)
  • The Web proxy will need to be able to do a Websocket upgrade on all of the above.

Issue 3: when trying to connect to another person, it just says "is being connected" but it never connects

Analysis: you have decided to close all UDP ports and your firewall does deep packet inspection therefore a connection cannot be established.

Remedy: ask your network administrators to do one of two things: either open up some UDP ports or make sure you can connect to our TURN server even when your firewall requires authentication and does deep packet inspection. 

  1. Open UDP ports in the media range 49152 to 65535. This will often reduce audio/video latency because it avoids the use of a forwarding server and enables direct peer to peer connections.
  2. If you cannot open UDP ports, our platform will try to connect to our TURN servers on port 443 (not unlike a VPN). These domains need to be added to your proxy (required - to reach TURN servers):
  3. If adding the TURN servers to the proxy is not sufficient, you are likely using deep packet inspections and throwing away the video packets on port 443. Therefore, you will need to add the TURN IP addresses to the bypass list on your proxy:
    5. Twilio TURN IP ranges can be found here:

TIP: This list may need to be refreshed if the TURN servers change IP addresses. But at least you don't have to open up the UDP ports.


You have completed another Coviu help article. You now know the firewall requirements required to use Coviu.

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If you still require any assistance, please do not hesitate to get in touch with our friendly Customer Success team using any of the contact methods available here.