[Freeswitch-dev] question about CNG on late packages

[Peter Olsson]

There are lots of probable causes to this. First of all, the timing in your server might be bad. What does timer_test return? Is this a real machine, or is it a virtual one?

I agree with the others saying that the CNG itself is probably not a problem. However, I know a minor changes was made some months back (in head) that made sure not to cause holes after a CNG frame was handled (I know, since I was the one reporting the issue - and it was fixed by Tony). But this problem didn't really cause bad audio, it made the audio disappear for a few seconds.

First of all, make sure you are using a current version, and not something from way back. If the issue still exist, and the timing on the machine seems ok, and you are not on a virtual server, please add logs and pcaps to a Jira issue. You might also need to enable some extra RTP debugging features in the RTP stack to get all logs needed.

/Peter

________________________________
Från: freeswitch-dev-bounces at lists.freeswitch.org [freeswitch-dev-bounces at lists.freeswitch.org] för Xijing Dai [dxj19831029 at gmail.com]
Skickat: den 5 februari 2013 17:48
Till: freeswitch-dev at lists.freeswitch.org
Ämne: Re: [Freeswitch-dev] question about CNG on late packages

by the way, what is the latency in ms to determine if a packet is late?


Our ptime is 10ms, and the sender always sends packets in 8-12ms.

And I did use wireshark to capture packets on freeswitch server, no lost packet is found before reaching freeswitch.

When our ptime is 20ms, it gets better, but still has CN.

When we are using proxy/proxy media, every thing works great.

when sample rate is 16000, the quality of call is worst.  8000 gets better.


Any other suggestions?

On Wed, Feb 6, 2013 at 12:32 AM, Xijing Dai <dxj19831029 at gmail.com<mailto:dxj19831029 at gmail.com>> wrote:
I see.


I did set it suppress_cng=true, and it did not help. No difference at all.

This happens inside LAN.

When talking about the jitter buffer, we want to enable it on client, and disable it inside freeswitch.
Therefore, in this case, should freeswitch do nothing?


Cheers




On Tue, Feb 5, 2013 at 11:35 PM, Anthony Minessale <anthony.minessale at gmail.com<mailto:anthony.minessale at gmail.com>> wrote:
Don't negotiate CNG in the SDP and it won't use it or disable it with suppress_cng=true in your channel or global vars.



On Tue, Feb 5, 2013 at 4:32 AM, Steven Ayre <steveayre at gmail.com<mailto:steveayre at gmail.com>> wrote:
Because if a RTP packet is due and hasn't arrived yet you need something to play. Audio isn't like TCP where you dropped packets can be retransmitted, if it hasn't arrived by the time you want to play it it's too late and you have to play silence to handle it.

Your audio problems are more likely due to packet loss or jitter which is why the RTP packet is overdue, not the CNG itself.

It jitter's the problem enabling the jitterbuffer might help (at the expense of increased lag). If loss is the problem there's no way to handle that except as silence for the missing interval, you need to fix whatever is causing the loss.

-Steve


On 5 February 2013 10:23, Xijing Dai <dxj19831029 at gmail.com<mailto:dxj19831029 at gmail.com>> wrote:
Hey all,


Inside code

switch_rtp.c file:

   static int rtp_common_read(switch_rtp_t *rtp_session, switch_payload_t *payload_type, switch_frame_flag_t *flags, switch_io_flag_t io_flags)
                 ................
                 if (check || (bytes && !switch_test_flag(rtp_session, SWITCH_RTP_FLAG_USE_TIMER))) {
if (!bytes && switch_test_flag(rtp_session, SWITCH_RTP_FLAG_USE_TIMER)) { /* We're late! We're Late! */
if (!switch_test_flag(rtp_session, SWITCH_RTP_FLAG_NOBLOCK) && status == SWITCH_STATUS_BREAK) {
switch_cond_next();
continue;
}

return_cng_frame();  <------- this lane to return cng frame if late.
}
}


Could someone explain why we want to return cng frame when package is late? this is caused for me to hear very bad noise audio.

Can I disable return CNG frame?


Cheers





_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting at freeswitch.org<mailto:consulting at freeswitch.org>
http://www.freeswitchsolutions.com




Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-dev mailing list
FreeSWITCH-dev at lists.freeswitch.org<mailto:FreeSWITCH-dev at lists.freeswitch.org>
http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-dev
http://www.freeswitch.org



_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting at freeswitch.org<mailto:consulting at freeswitch.org>
http://www.freeswitchsolutions.com




Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-dev mailing list
FreeSWITCH-dev at lists.freeswitch.org<mailto:FreeSWITCH-dev at lists.freeswitch.org>
http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-dev
http://www.freeswitch.org




--
Anthony Minessale II

FreeSWITCH http://www.freeswitch.org/
ClueCon http://www.cluecon.com/
Twitter: http://twitter.com/FreeSWITCH_wire

AIM: anthm
MSN:anthony_minessale at hotmail.com<mailto:MSN%3Aanthony_minessale at hotmail.com>
GTALK/JABBER/PAYPAL:anthony.minessale at gmail.com<mailto:PAYPAL%3Aanthony.minessale at gmail.com>
IRC: irc.freenode.net<http://irc.freenode.net> #freeswitch

FreeSWITCH Developer Conference
sip:888 at conference.freeswitch.org<mailto:sip%3A888 at conference.freeswitch.org>
googletalk:conf+888 at conference.freeswitch.org<mailto:googletalk%3Aconf%2B888 at conference.freeswitch.org>
pstn:+19193869900<tel:%2B19193869900>

_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting at freeswitch.org<mailto:consulting at freeswitch.org>
http://www.freeswitchsolutions.com




Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-dev mailing list
FreeSWITCH-dev at lists.freeswitch.org<mailto:FreeSWITCH-dev at lists.freeswitch.org>
http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-dev
http://www.freeswitch.org



!DSPAM:511134c132767372939513!