The negotiation for audio looks like this:
ortp-message-cb_snd123456xx (id=1)
Connected.
linphonec> ortp-message-Call 0x6b8a8: moving from state LinphoneCallIncomingReceived to LinphoneCallConnected
Call 1 with <sip:pgre...@10.128.84.155> connected.
ortp-message-Audio bandwidth for this call is 44
ortp-message-speex_lib_ctl does not support SPEEX_LIB_CPU_FEATURE_NEON
ortp-message-cb_nict_kill_transaction (id=1)
ortp-message-eXosip: timer sec:0 usec:648457!
ortp-message-Payload's bitrate is 44000
ortp-message-Setting audio encoder network bitrate to 44000
ortp-message-ms_filter_link: MSAlsaRead:0x70e98,0-->MSSpeexEC:0x81250,1
ortp-message-ms_filter_link: MSSpeexEC:0x81250,1-->MSVolume:0x6fa98,0
ortp-message-ms_filter_link: MSVolume:0x6fa98,0-->MSSpeexEnc:0x6bcd0,0
ortp-message-ms_filter_link: MSSpeexEnc:0x6bcd0,0-->MSRtpSend:0x70f20,0
ortp-message-ms_filter_link: MSRtpRecv:0x789b8,0-->MSSpeexDec:0x6fa20,0
ortp-message-ms_filter_link: MSSpeexDec:0x6fa20,0-->MSDtmfGen:0x810b8,0
ortp-message-ms_filter_link: MSDtmfGen:0x810b8,0-->MSVolume:0x6be68,0
ortp-message-ms_filter_link: MSVolume:0x6be68,0-->MSEqualizer:0x6bed0,0
ortp-message-ms_filter_link: MSEqualizer:0x6bed0,0-->MSSpeexEC:0x81250,0
ortp-message-ms_filter_link: MSSpeexEC:0x81250,0-->MSAlsaWrite:0x76540,0
ortp-message-Initializing speex echo canceler with framesize=64, filterlength=4000, delay_samples=0
ortp-message-Setting maxbitrate=28000 to speex encoder.
ortp-message-Using bitrate 27800 for speex encoder, ip bitrate is 43600
ortp-message-Priority used: 99
ortp-message-Audio MSTicker setpriority() failed: Permission denied, nevermind.
ortp-message-Filter MSRtpRecv is already being scheduled; nothing to do.
ortp-message-Call 0x6b8a8: moving from state LinphoneCallConnected to LinphoneCallStreamsRunning
Media streams established with <sip:pgre...@10.128.84.155> for call 1.
ortp-message-call answered.
linphonec> ortp-message-alsa_open_r: opening default at 16000Hz, bits=16, stereo=0
xcb_connection_has_error() returned true
ortp-message-Received message:
ACK sip:deb...@10.128.84.154 SIP/2.0
Via: SIP/2.0/UDP 10.128.84.155:5060;rport;branch=z9hG4bK.FHinVVo8u
From: <sip:pgre...@10.128.84.155>;tag=gm8PDvkzI
To: <sip:deb...@10.128.84.154>;tag=1705673520
CSeq: 20 ACK
Call-ID: 7x78li-cQI
Max-Forwards: 70
ortp-message-Message received from: 10.128.84.155:5060
ortp-message-Message received from: 10.128.84.155:5060
ortp-message-MESSAGE REC. CALLID:7x78li-cQI
ortp-message-Message received from: 10.128.84.155:5060
ortp-message-This is a request
ortp-message-linphone process event get a message 15
ortp-message-CALL_ACK
ortp-message-eXosip: timer sec:0 usec:547862!
ortp-warning-alsa_set_params: periodsize:512 Using 512
ortp-warning-alsa_set_params: period:8 Using 8
ortp-message-alsa_open_r: Audio params set
ortp-message-ms_ticker_set_time_func: ticker updated.
ortp-warning-Getting reference signal but no echo to synchronize on.
ortp-warning-Not enough ref samples, using zeroes
ortp-message-alsa_open_w: opening default at 16000Hz, bits=16, stereo=0
xcb_connection_has_error() returned true
ortp-warning-alsa_set_params: periodsize:512 Using 512
ortp-warning-alsa_set_params: period:8 Using 8
ortp-message-bandwidth usage: audio=[d=0.0,u=0.0] video=[d=0.0,u=0.0] kbit/sec
ortp-message-Thread processing load: audio=129.954559 video=0.000000
ortp-message-alsa_open_w: Audio params set
My configuration for Linphone is the default it creates when started:
debian@beaglebone:~$ cat .linphonerc
[sip]
media_encryption=none
guess_hostname=1
contact=sip:debian@unknown-host
inc_timeout=15
use_info=0
use_rfc2833=0
use_ipv6=0
register_only_when_network_is_up=1
[net]
download_bw=0
upload_bw=0
firewall_policy=0
mtu=0
[call_log_0]
dir=1
status=0
from=<sip:pgre...@10.128.84.155>
to=<sip:deb...@10.128.84.154>
start_date=Thu Oct 29 12:23:34 2015
duration=14
quality=1.889588
[rtp]
audio_rtp_port=7078
video_rtp_port=9078
audio_jitt_comp=60
video_jitt_comp=60
nortp_timeout=30
[sound]
remote_ring=/usr/share/sounds/linphone/ringback.wav
[video]
size=cif
display=0
capture=0
show_local=0
self_view=1
[audio_codec_0]
mime=speex
rate=32000
enabled=1
[audio_codec_1]
mime=speex
rate=16000
enabled=1
[audio_codec_2]
mime=speex
rate=8000
enabled=1
[audio_codec_3]
mime=GSM
rate=8000
enabled=1
[audio_codec_4]
mime=PCMU
rate=8000
enabled=1
[audio_codec_5]
mime=PCMA
rate=8000
enabled=1
[audio_codec_6]
mime=L16
rate=44100
enabled=0
[audio_codec_7]
mime=L16
rate=44100
enabled=0
[audio_codec_8]
mime=G722
rate=8000
enabled=0
[video_codec_0]
mime=MP4V-ES
rate=90000
enabled=1
recv_fmtp=profile-level-id=3
[video_codec_1]
mime=H263-1998
rate=90000
enabled=1
recv_fmtp=CIF=1;QCIF=1
[video_codec_2]
mime=theora
rate=90000
enabled=0
[video_codec_3]
mime=x-snow
rate=90000
enabled=0
[video_codec_4]
mime=H263
rate=90000
enabled=0
[call_log_1]
dir=1
status=0
from=<sip:pgre...@10.128.84.155>
to=<sip:deb...@10.128.84.154>
start_date=Thu Oct 29 12:21:51 2015
duration=29
quality=3.969424