# RTSP/RTP streaming through NAT **URL:** \ **Category:** Wowza Streaming Engine\ **Created:** [February 11, 2019, 4:58pm UTC](https://community.wowza.com/t/rtsp-rtp-streaming-through-nat/52833 "2019-02-11T16:58:23Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Sergey\_Nazaryev](https://avatars.discourse-cdn.com/v4/letter/s/b77776/32.png) [@Sergey\_Nazaryev](https://community.wowza.com/u/Sergey_Nazaryev)\ **Post date:** [February 11, 2019, 4:58pm UTC](https://community.wowza.com/t/rtsp-rtp-streaming-through-nat/52833/1 "2019-02-11T16:58:23Z")
Hi! I have “Wowza Streaming Engine” EC2 instance on Amazon. My phone tries to connect to this instance over LTE using RTSP/RTP method and the connection works only through TCP. But we want to make it work via UDP. I discovered that carrier NAT changes source port of UDP packets to random one and my phone receives “Destination unreachable (Port unreachable)” packets when tries to send UDP packets to Wowza instance. However, this test stream ([https://www.wowza.com/html/mobile.html](https://www.wowza.com/html/mobile.html)) works well over UDP. I think that Wowza expects as a source port the one that was transfered via RTSP (Transport: RTP/AVP;unicast;client\_port=57780-57781). But instead, it receives a random one that was set by carrier NAT. What should I change in Wowza settings to fix this issue? Thank you in advance! ---
**Author:** ![system](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/system/32/447_2.png) [@system](https://community.wowza.com/u/system)\ **Post date:** [February 11, 2019, 8:05pm UTC](https://community.wowza.com/t/rtsp-rtp-streaming-through-nat/52833/2 "2019-02-11T20:05:19Z")
We have a troubleshooting article that shows which UDP ports are most commonly used with RTSP. I have linked directly the relevant portion below. [https://www.wowza.com/docs/how-to-troubleshoot-wowza-streaming-engine-installation#network](https://www.wowza.com/docs/how-to-troubleshoot-wowza-streaming-engine-installation#network)