Holger, Anthony, I'm seeing a similar/identical 'feature' where the voice is intermittently broken on ISDN; I've raised ticket #1310 with Sangoma. My MTU is still on the default 80 but there is no IDLE_FLAG setting (default 0, I guess?). Interestingly(!), it is intermittent and unpredictable, but when it manifests there is no clear pattern as to what will be disrupted; A wav audio played by a Lua IVR will be fine, then on the same call the MOH will be broken, as will the voicemail outgoing message and finally the internal user's speech. The path from ISDN into FreeSWITCH is never disrupted (no surprise). Record_session doesn't show the breaks and there's nothing in the FS logs. I have sample audio taken from another (SIP only) FreeSWITCH instance which demonstrates the problem, but as the fault is intermittent and on a production system, debugging is taking some time. Sangoma has asked me to take samples at the ISDN (S?) interface and the echo canceller on the B700 board. When I next have the problem manifest, and grab those traces, I should be able to share the results once Sangoma has decoded them. I can make available the audio samples I already have if that would help. John On 10/02/12 21:24, Anthony Minessale wrote:
That made no sense in regards to my last message.
I asked you to try particular wanpipe parameters, so you should try them and restart your wanpipe and report the results. Your MTU is very high and may cause timing issues for interop with voip.
set MTU to 80 (10ms) set IDLE_FLAG to 0xFF (send the 255 byte on idle stream)
1) Turn off FreeSWITCH 2) wanrouter stop 3) wanrouter start 4) start FreeSWITCH
You are pushing RTP up against TDM, RTP can start and stop, TDM cannot, When there is no RTP the TDM will carry on sending the IDLE_FLAG byte over the wire.
I made both the RTP stack and the TDM endpoint from scratch so you should assume I may have some insight.
On Fri, Feb 10, 2012 at 12:28 PM, Holger Freyther<holger@freyther.de> wrote:
Anthony Minessale<anthony.minessale@...> writes:
If there is no RTP then the TDM should be generating its own audio.
Try
MTU = 80 IDLE_FLAG = 0xFF Writing about audio is difficult. Imagine one says the word "Two".. and one called a mailbox. Opening the file in audacity gives you the wave of what you said, you zoom in and you see that in the middle of the word the the amplitude is zero for a bit (where it should not be zero). As echoing works on FreeTDM, there is no packet loss in RTP, the bug has the whole audio... it means something is broken in FreeSWITCH to get the audio to FreeTDM in time?
Any ideas?