[Asterisk-Dev] IAX vs. IAX2 - problems and notes

[John Todd]

Setting jitterbuffer=1  in my iax.conf files on both ends seems to 
make a difference for the call dropouts.  However, I have been having 
other IAX/IAX2 issues which have been vexing me lately so I will 
admit I have not experimented with this fix extensively.    (other 
problems are relating to how hangups and timeouts are treated within 
IAX - trying to get these worked out with mark.)

JT


>While the communciation is excellent with IAX2 I have had similar experience
>with audio drop-offs fairly frequent.
>Have you gotten any feedback or further tests? Is there any params to play
>with on iax.conf?
>
>
>
>
>----- Original Message -----
>From: "John Todd" <jtodd at loligo.com>
>To: <asterisk-dev at lists.digium.com>
>Cc: <markster at digium.com>
>Sent: Saturday, May 03, 2003 8:35 PM
>Subject: [Asterisk-Dev] IAX vs. IAX2 - problems and notes
>
>
>>
>>  I've done some testing with both IAX and IAX2 between endpoints, and
>>  I've noticed some differences:
>>
>>  1) IAX2 doesn't seem to have "comfort noise", while IAX seems to have
>>  a steady background "hiss" which is what I'd expect on a phone
>>
>>  2) IAX2 has some serious sound squelching/clipping that interferes
>>  with call audio.  It almost appears that IAX2 is half-duplex.  If the
>>  other end of the line is talking, I can't break in to the
>>  conversation and talk over them or interrupt; I have to wait until
>>  they're done talking before I can be heard, unless I shout into the
>>  phone and create a "louder" noise.  This may be related to #1.
>>
>>  3) IAX2 seems to drop the audio fairly frequently in intermittent
>>  intervals.  If I am silent for too long, the audio from the far end
>>  stops, and I'm left with a silent line.  I then need to "create a
>>  noise" like blowing into the microphone or say "HEY!" into the
>>  microphone for the audio to start up again where I can hear the far
>>  end.  Needless to say, this is very disconcerting to myself and the
>>  other party.  This may be related to #1 and #2.
>>
>>  4) IAX2 has better sound quality, as far as clarity of the voices on
>>  the channel.
>>
>>  5) IAX2 and IAX have broken "jitter" and "lag" variables; they often
>>  jump up into numbers like 65123ms, which is obviously false.  This
>>  normally happens after a few minutes of conversation time.
>>
>>  6) IAX2 will often drop one side of the conversation completely.
>>  Normally, when I initiate the call, it is my audio channel that will
>>  be lost. I can hear the other end, but they cannot hear me.  We hang
>>  up, and try again.
>>
>>
>>  My experiences with these issues are relative to my configuration, of
>>  course, which is normally SIP (G.711, Cisco ATA-186) -> * -> IAX -> *
>>  -> SIP (G.711, Cisco 79xx)  However, they are real issues for me, and
>>  warrant some further data from anyone else out there with the same
>>  problems.  If more than one person has seen the same problems, I'd
>>  like to talk with them about it.  I've already found one person
>>  (tclark) who has reported some of the symptoms, and I'd like to find
>>  others so that we can present a better view of the issues to Mark (or
>>  anyone else) who might be able to narrow them down
>>
>>  JT
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