[Ekiga-list] Very choppy sound with sip:500 at ekiga.net

[JCA]

    After posting this I noticed that choppy sound seems to be a very
common issue with Ekiga. I therefore followed some suggestions that I
found in my search.

    First, modifying my /etc/asound.conf file for accounting for the
DMIX issue makes no difference (I believe this is not applicable to my
kernel version anyway). Actually, it seems to make Ekiga behave worse,
in that it occasionally freezes up.

   Second, the test line

     arecord -D plughw:0,0 -c 1 -r 8000 -f S16_LE - | aplay -D plughw:0,0 -c
     1 -r 8000 -f S16_LE -

works fine. With a faint echo, but otherwise fine.

    Third, I tried with all the audio codecs that Ekiga has to offer,
and the only one that seems to work (with very choppy sound, like I
said) is PCMA.

   Fourth, I tinkered with the jitter buffers parameters, and I could
notice a very slight improvement when the parameters were 20 and 20 -
i.e. when disabled, I believe. The sound still is unacceptably choppy
tough.

   Fifth, the echo cancellation option makes no difference one way or the other.

   Sixth, after the connection with the SIP echo server gets
established, according to the Ekiga statistics no packets are dropped,
and the jitters buffers values oscillate between 20ms and 100ms.

   Seventh, Ekiga never takes up more than 10% of the CPU time (this
is on a 3.2 GHz Pentium 4).

   Eighth, my pings to ekiga.net take less than 180ms, and there is a
0% packet loss.

   This is all on Slackware 11, with a 2.6.19.1 kernel, for which the
ALSA version seems to be 1.0.13



On 1/11/07, JCA <1.41421 at gmail.com> wrote:
>     OK, here is my problem:
>
>     I am running Ekiga 2.0.3 on a Linux box under a 2.6.19.1 kernel.
> My ADSL line does 330 KB/s downstream, 50 KB/s upstream. I am behind a
> firewall that Ekiga detects as Port Restricted NAT, so I have enabled
> STUN support, because my modem does not support SIP or H.323 natively.
> The sound hardware is a built-in Intel ICH5 device.
>
>    Everything seems to be fine. The network runs flawlessly, and so
> does the sound device. In particular, when I run the sound test from
> within the Ekiga druid, I can hear my voice echoed back, without no
> distortion whatsoever, after a few seconds.
>
>    However, when I call sip:500 at ekiga.net the sound received is
> extremely choppy - the voice is barely intelligible. It is as though
> the person at the other side were underwater. My voice gets to the
> other side all right, but it is echoed back with the same distortion.
>
>    I notice that Ekiga selects the PCMA audio codec. If I disable this
> codec in my preferences then I get not sound at all in my call (other
> than the dial tone) despite of the fact that the connection gets
> established fine.
>
>   Any suggestions on how to fix this issue? What makes it even more
> irksome is that Skype works without any distortion on this Linux box -
> I am trying to get a few acquaintances to look into Ekiga, and under
> these conditions I don't stand much of a chance.
>