Ipfire blocks some of the RTSP traffic after upgrade

Networking
1

Hi there,

I have a setup where a VLC player is playing (from time to time) an IP camera RTSP stream over a Network-to-network VPN connection, and that setup was working for many years (correct, many years :wink: ).
The problem is that after one of the upgrades, however the stream cannot be played correctly anymore - the stream freezes and just few frames per minute are displayed.
I “suspect” that the problem has appeared when QoS was introduced (around Core Uptade 137) but I’m NOT sure.
I did some tests with different devices (including a mobile phone) to play the same RTSP camera stream and the result is:

  1. RTSP stream is played correctly when both devices (vlc player and the camera) are on the same lan
  2. RTSP stream is freezing (or just showing 2-3 frames per minute) when RTSP is going through ipfire (tested with N2N connection, road warrior VPN connections and from green to orange).

Based on that I have a question - How can I test if ipfire is blocking (or not forwarding correctly) the RTSP traffic or not?

Many thanks in advance!

2

Hi,

welcome to the IPFire community.

I “ suspect ” that the problem has appeared when QoS was introduced (around Core Uptade 137) but I’m NOT sure.

Hm, does the problem persists if you disable QoS and reboot your IPFire machine?

Besides, this suspiciously sounds like being related to bug #12442, but having little experience with RTSP, I am not sure either.

Based on that I have a question - How can I test if ipfire is blocking (or not forwarding correctly) the RTSP traffic or not?

Since RTSP traffic is just UDP or TCP (to my surprise, this is standardised as well), it should show up in the firewall log in case it is blocked by IPFire. In case you do not trust the GUI or need more detailed information, looking at the interfaces themselves via tcpdump might be helpful.

Thanks, and best regards,
Peter Müller

3

Hi Peter, team,

Thank for the prompt reply. It took me some time to test different configurations and to “implement” your suggestions.
However, what I did is the following:

Run different tests (N2N, RW vpn, green to Orange, different players, different codecs (h264, h265)) with the same result - when the traffic goes through ipfire, the stream is broken.
I doublechecked QoS settings - I have never used QoS (the service is stopped).

If ipfire is blocking(not forwarding correctly) RTSP traffic, how can I “detect” that behaviour?

4

bump
maybe debugging with iptables or …something else

1 Like
5

Try to allow p2p networks. This filters tend to misdetect some streams.

1 Like
6

Tried with no success.
Probably I have to do some reading about RTSP and iptables before debugging it. :wink:

Thanks for the suggestions guys.

1 Like