Hello Jeroen,
welcome to the Polycom Community.
There are multiple topics covering the same issue within this community already that can be found via the community search => here <=.
The community's Video FAQ contains this post here:
Jun 21,2014 Question: What could be causing one way video or one way audio when utilizing video conferencing?
Answer: Please check the relevant release notes or admin guide for your device under the section “Inbound and Outbound Ports” or "Port usage" => here <= in order to open the relevant firewall ports.
Please ensure you always check the community FAQ and/or utilize the community search before posting any new topics or follow up post’s.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Best Regards
Steffen Baier
Polycom Global Services
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If official support is required please check how to phone or open a case here
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The title Poly Employee & Community Manager is a community setting and
does not reflect my role. I am just a simple volunteer in the community like everybody else. All posts and words are my own & do not represent the views of Employer.
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Notice: This community forum is not an official Poly support resource, thus responses from Poly employees, partners, and customers alike are best-effort in attempts to share learned knowledge. If you need immediate and/or official assistance please open a service ticket through your proper support channels.
Please also ensure you always check the VoIP , Video Endpoint , Skype for Business , PSTN or RPM FAQ's
