a note for linphone users who want to use the freeswitch server

a note for linphone users who want to use the freeswitch server

[Christopher Brannon]

Hello,
Several of us have noticed a problem with linphone when using the new
voice chat server on linux-speakup.org.
Specifically, if there are no other participants in the conference, or
all of the other participants have muted their outbound audio, linphone
automatically disconnects after 30 seconds or so.
It is quite annoying.
I found the workaround this afternoon.
Edit ~/.linphonerc, and look for the line that says:
nortp_timeout=30
You should change the 30 to something higher when using the freeswitch
conference.  I set it to 7200.
Yes, this is just a workaround.  I'm not convinced that it is the best
permanent solution.

Hope this helps,
-- Chris

Re: a note for linphone users who want to use the freeswitch server

[William Hubbs]

On Mon, Feb 07, 2011 at 11:49:15PM +0000, Christopher Brannon wrote:
> Hello,
> Several of us have noticed a problem with linphone when using the new
> voice chat server on linux-speakup.org.
> Specifically, if there are no other participants in the conference, or
> all of the other participants have muted their outbound audio, linphone
> automatically disconnects after 30 seconds or so.
> It is quite annoying.
> I found the workaround this afternoon.
> Edit ~/.linphonerc, and look for the line that says:
> nortp_timeout=30
> You should change the 30 to something higher when using the freeswitch
> conference.  I set it to 7200.
> Yes, this is just a workaround.  I'm not convinced that it is the best
> permanent solution.

There used to be music that played when you entered the conference and
were the only one there; that may be a good reason to think about
bringing it back some how.

William

Re: a note for linphone users who want to use the freeswitch server

[Christopher Brannon]

William Hubbs <w.d.hubbs@gmail.com> writes:

> There used to be music that played when you entered the conference and
> were the only one there; that may be a good reason to think about
> bringing it back some how.

If there's nobody there, I would personally rather hear silence, so that
I can play a stream of my choosing.  Plus, playing music wastes
bandwidth.
Note that the problem also occurs if the other participants mute their
outbound audio.  I.E., no audio is being sent by the server.
The best solution is a keep-alive message of some sort.  I.E., every X
number of seconds, the freeswitch conference module sends a packet to
every connected user, saying "Hey, I'm alive".  SIP doesn't have a
keep-alive feature.  linphone automatically disconnects when X seconds
have elapsed since the last RTP packet.  The default value of X is 30.
RTP is the protocol which actually carries the audio (or video) data.
So here's the question.
Would it be possible to send an RTP packet consisting of nothing but
silence to every participant at a given interval?  This wouldn't require
much bandwidth, and it would give us the equivalent of keep-alive.

-- Chris