# Empty Video output despite active stream **URL:** \ **Category:** Wowza Streaming Engine\ **Created:** [October 1, 2014, 8:43pm UTC](https://community.wowza.com/t/empty-video-output-despite-active-stream/44060 "2014-10-01T20:43:11Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![John\_Monterubio](https://avatars.discourse-cdn.com/v4/letter/j/50afbb/32.png) [@John\_Monterubio](https://community.wowza.com/u/John_Monterubio)\ **Post date:** [October 2, 2014, 3:29pm UTC](https://community.wowza.com/t/empty-video-output-despite-active-stream/44060/4 "2014-10-02T15:29:53Z")
I finally fixed the issue (see the Cornell BirdCam at [https://reefcam.tv/](https://reefcam.tv/)). I had to change the rtpTransportMode under the RTSP properties for the stream file from the default (UDP) to RTP. This solved the issue. My guess was that the firewall was blocking the UDP ports. By not using UDP we avoided being blocked on those ports. However, I’m not sure if this was exactly the reason. I had the idea to change the rtpTransportMode based on these threads. > [@Streaming Through Firewall](http://community.wowza.com/t/-/34602): > > I want to stream H.264 content through a firewall. I am using Axis M10 series cameras. I can not manually configure the firewall. Any solution that involves programatic configuration of the firewall is welcome. I just cant do this manually, since our customers are not technical people and they dont know how to setup. I wanted to try RTP/RTSP tunneling over HTTP. But I saw in Wowza forums that Wowza can not take RTP/RTSP over HTTP data as input. It can stream out data through http to play… > **[Specify per-stream settings in .stream files](https://www.wowza.com/docs/how-to-specify-per-stream-settings-in-stream-files)** > > Set up per-stream settings in .stream files for MPEG-TS encoders and IP cameras (RTSP/RTP streams), SHOUTcast/Icecast streams, native RTP encoders. --- _[View the full topic](https://community.wowza.com/t/empty-video-output-despite-active-stream/44060)._