improving transport over lossy links ?

[Julian Elischer]

Ian Smith wrote:

>On Fri, 19 May 2006 at 11:06:48 -0400, Mike Tancsa wrote:
>
> > I am looking for a way to improve the reliability of a lossy link 
> > (dialup from remote sites). I am going to try multilink PPP but was 
> > wondering if something like ng_one2many might work as well ?  Does 
> > anyone have any suggestions for avenues to explore ?  For multilink 
> > ppp, does mpd offer any better performance / reliability over the stock ppp ?
>
>No idea whether these options may help, but ..
>  
>

mpd does well, bit keep the mtu on the interface relatively small if you 
have a lot of line noise.
I have not tried ppp with multilink.

> 
> > The application is low bandwidth, but doesnt deal that well with 
> > packet loss and the phone lines in these remote locations tend to be 
> > noisy and drop connections frequently.
>
>If by 'drop connections' you mean physical loss of line / carrier, then
>tuning the modem/s to be (preferably much) less aggressive about forcing
>the modem connection rate high - ie being easily satisfied to drop back
>to lower rates during hard times - has helped a lot with a dozen or so
>remote spots hereaboots.  Finding the knobs for some modems can be hard.
>
>Assuming that V.42 error correction is working properly - forced if need
>be - there shouldn't =be= any data loss, however slow getting through,
>this side of protocol timeouts of course.  I can't guess your mystery
>application, but often slower connections are better than dropped ones,
>or even ones that spend half their time trying to retrain at high rates.
>
>cheers, Ian
>
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>