[Asterisk-Dev] Increasing reliability on lossy connections

[Mike M]

On Wed, Jan 12, 2005 at 02:07:31PM -0500, John Todd wrote:
> At 12:54 PM -0600 1/12/05, Michael Giagnocavo wrote:
> >
> >So, what I was thinking is that if duplicate IAX2 packets were sent, then
> >most packets would get there, at least once. IAX2 would discard the
> >duplicates, and things would work better, at double the bandwidth. I was
> >thinking about adding an iax.conf option to configure this per user.
> 
> The better solution would be to implement iLBC's packet concealment 
> methods, and then use that codec for your IAX2 trunking.  I am 
> currently under the impression (someone correct me if I'm wrong! 
> It's been a while since this was discussed...) that the iLBC code in 
> * is not completely implemented due to timing issues, so that iLBC's 
> great packet concealment methods are unused.
> 
> Sending packets twice is... a frightening hack.

Actually  it's a small form of the PCR error correction method used on
satellite links.  Preventive Cyclic Retransmission periodically resends 
unacknowledged PDUs until they are ack'd.

-- 
Mike