Hello Arsen,
thank you very much for your effort on investigating this problem.
I have some interesting findings:
In my case the problem depends on the SIP phone that I am using on my mobile, i.e.:
1. IPhone 5s with Zoiper Lite v3.21 - problem exists
2. Samsung S7 with Zoiper IAX SIP VOIP v 2.7.12 - problem exists
3. IPhone 5s with VaxPhone v8.6.0.2 - problem does NOT exist
4. Samsung S7 with MizuDroid - initial problem does not exist, except that the initial prompt is cut at the beginning (better than cut at the end as this influences recognition ;)) - see asterisk logs
-- Executing [631@from-internal:1] Answer("SIP/6001-0000000a", "") in new stack
[Mar 26 08:58:12] WARNING[4927][C-0000000b]: res_rtp_asterisk.c:6627 ast_rtp_read: RTP Read too short
[Mar 26 08:58:12] WARNING[4927][C-0000000b]: res_rtp_asterisk.c:6627 ast_rtp_read: RTP Read too short
[Mar 26 08:58:12] WARNING[4927][C-0000000b]: res_rtp_asterisk.c:6627 ast_rtp_read: RTP Read too short
[Mar 26 08:58:12] WARNING[4927][C-0000000b]: res_rtp_asterisk.c:6627 ast_rtp_read: RTP Read too short
-- Executing [631@from-internal:2] SpeechCreate("SIP/6001-0000000a", "") in new stack
Also, what is interesting is that for the problematic cases, first execution of SpeechBackground is causing the problem, i.e. the prompt is interrupted and recognition doesn't give proper result, however if dialplan proceeds further where there are other calls to SpeechBackground, these work fine.
I also provide you with log from tcpdump for the faulty case nr 2.
I am using 8kHz speech recog model.
And I haven't tried with MRCPRecog but I can still try to see whether it changes something.
Do you think that we should further investigate that or simply assume that these are problems with the clients?
Ultimately I would like to make phone calls from the mobile without using SIP client, but using GSM network, hence that's what interests me the most. I just need to figure out first how to do this, and I can provide information how this works.
Thank you Arsen!
Ernest