Thu Apr 28 2011 17:14:04

Asterisk developer's documentation


ALSA configuration

alsa.conf

  • Implemented in chan_alsa.c
    ;
    ; Open Sound System Console Driver Configuration File
    ;
    [general]
    ;
    ; Automatically answer incoming calls on the console?  Choose yes if
    ; for example you want to use this as an intercom.
    ;
    autoanswer=yes
    ;
    ; Default context (is overridden with @context syntax)
    ;
    context=local
    ;
    ; Default extension to call
    ;
    extension=s
    ;
    ; Default language
    ;
    ;language=en
    ;
    ; Default Music on Hold class to use when this channel is placed on hold in
    ; the case that the music class is not set on the channel with
    ; Set(CHANNEL(musicclass)=whatever) in the dialplan and the peer channel
    ; putting this one on hold did not suggest a class to use.
    ;
    ;mohinterpret=default
    ;
    ; Silence suppression can be enabled when sound is over a certain threshold.
    ; The value for the threshold should probably be between 500 and 2000 or so,
    ; but your mileage may vary.  Use the echo test to evaluate the best setting.
    ;silencesuppression = yes
    ;silencethreshold = 1000
    ;
    ; To set which ALSA device to use, change this parameter
    ;input_device=hw:0,0
    ;output_device=hw:0,0
    
    ;------------------------------ JITTER BUFFER CONFIGURATION --------------------------
    ; jbenable = yes              ; Enables the use of a jitterbuffer on the receiving side of an
                                  ; ALSA channel. Defaults to "no". An enabled jitterbuffer will
                                  ; be used only if the sending side can create and the receiving
                                  ; side can not accept jitter. The ALSA channel can't accept jitter,
                                  ; thus an enabled jitterbuffer on the receive ALSA side will always
                                  ; be used if the sending side can create jitter.
    
    ; jbmaxsize = 200             ; Max length of the jitterbuffer in milliseconds.
    
    ; jbresyncthreshold = 1000    ; Jump in the frame timestamps over which the jitterbuffer is
                                  ; resynchronized. Useful to improve the quality of the voice, with
                                  ; big jumps in/broken timestamps, usually sent from exotic devices
                                  ; and programs. Defaults to 1000.
    
    ; jbimpl = fixed              ; Jitterbuffer implementation, used on the receiving side of a SIP
                                  ; channel. Two implementations are currently available - "fixed"
                                  ; (with size always equals to jbmax-size) and "adaptive" (with
                                  ; variable size, actually the new jb of IAX2). Defaults to fixed.
    
    ; jbtargetextra = 40          ; This option only affects the jb when 'jbimpl = adaptive' is set.
                                  ; The option represents the number of milliseconds by which the new
                                  ; jitter buffer will pad its size. the default is 40, so without
                                  ; modification, the new jitter buffer will set its size to the jitter
                                  ; value plus 40 milliseconds. increasing this value may help if your
                                  ; network normally has low jitter, but occasionally has spikes.
    
    ; jblog = no                  ; Enables jitterbuffer frame logging. Defaults to "no".
    ;-----------------------------------------------------------------------------------