Telephony Firewall and Ports

Advice for customers facing telephony audio issues likely to be related to firewalls and ports

Faye avatar
Written by Faye
Updated over a week ago

If you are experiencing connection issues when using telephony where the call connects but you are unable to hear the patient and they are unable to hear you, this can be caused by firewalls blocking the inbound and outbound audio. Please share this with your IT team who should be able to unblock the necessary ports. If there are any questions please email:

IP requirements

Please head to the following guide here by our telephony provider, Vonage, and follow their instructions. If that does not resolve the issue, please then continue reading.

The first IP to unblock is: IP please then test the calling function again. If you are still facing issues then it might be the API products you are using are blocking IP ranges used for receiving HTTP callbacks, webhooks, WebSocket connections, SIP & Media signalling.

WebSocket (prioritising)

Port: All**

HTTP Callbacks


Port: UDP/TCP on 5060, TLS on 5061


Port: All**

SIP Callbacks

**If you are unable to allow all UDP ports, you can alternatively restrict the port range to 10000:50000.

Any questions or issues please contact the support team by email:, phone: 0330 223 0349 or pressing the pink dot:

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