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multicast join at startup

Posted: 19 Sep 2008 18:03
by yohann.martineau
hello,

i'm trying to make some tests with vlc used as a streaming server locally (i.e. without any network connection) and when my ethernet network cable is disconnected vlc client is very slow and sometimes crashes. I have connected my network cable again and I've seen (using wireshark) that several packets are sent to the multicast address 228.67.43.91 at vlc startup. I think it's intended... ?

Here are the packets:

- IGMP join group 228.67.43.91
- a udp packet containing "hostIdTest"

I don't know what it is for. Could it be the reason why vlc is slow when I'm playing files locally?
Is it employed to manage software updates?

Is it possible to deactivate those packets at startup?

Thanks a lot,

yohann

Re: multicast join at startup

Posted: 20 Sep 2008 10:52
by RĂ©mi Denis-Courmont
VLC does not join group 228.67.43.91, unless you requested it to open a stream on that group.

VLC may join some other groups at startup if you have enabled SAP and/or Bonjour service discovery.

Re: multicast join at startup

Posted: 22 Sep 2008 11:23
by yohann.martineau
ok.

Thank you for your reply, I do not open this multicast group manually. I did not activate bonjour/sap service discrovery. I'm not perfectly sure those packets are coming from vlc, but I don't understand why it's getting this slow when I disconnect the network (everything is done locally, using "localhost" address).

Re: multicast join at startup

Posted: 22 Sep 2008 13:35
by The DJ
This seems to be something that live555 (RTSP client of VLC) does. It's ttl=0 so shouldn't get passed the first router that is in your network.

http://www.live555.com/liveMedia/doxyge ... r_8hh.html

So basically, this might happen if you try to do something with rtsp:// links.

Re: multicast join at startup

Posted: 22 Sep 2008 15:00
by yohann.martineau
great! you're right, i'm using vlc as vlm to provide vod access using rtsp.

I will dig this point.