# Trouble with RTMFP

**URL:** <https://forum.kirupa.com/t/trouble-with-rtmfp/314416>\
**Category:** Uncategorized\
**Created:** [September 28, 2010, 8:11am UTC](https://forum.kirupa.com/t/trouble-with-rtmfp/314416 "2010-09-28T08:11:26Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aeon](https://avatars.discourse-cdn.com/v4/letter/a/57b2e6/32.png) [@aeon](https://forum.kirupa.com/u/aeon)\
**Post date:** [September 28, 2010, 8:11am UTC](https://forum.kirupa.com/t/trouble-with-rtmfp/314416/1 "2010-09-28T08:11:26Z")

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I make a video/text chat that based on RTMFP. It work very well, but for some users appeared error. They can connect to stratus server, but nobody can’t connect to him. In rtmfp test which located on [http://cc.rtmfp.net](http://cc.rtmfp.net) last line report about error “Source UDP port number is preserved from original connection”. In adobe docs I found some info about that error. Error occurs if user behind NAT which allow udp packet only in one side.  
Maybe someone known how avoid that error?