LibURL Error Previous request not completed

[Dar Scott]

On Aug 3, 2006, at 8:32 AM, Alex Tweedly wrote:

> Yes, it does matter. There are a number of cases where multiple  
> connections will win out :
>
> 1. avoiding start/finish round-trip delays for each transfer.
>      You don't of course avoid them - but you can interleave them  
> with the parallel transfers, and hence keep the pipe closer to full.
> 2. transient congestion (and packet-drops) have less effect on  
> multiple connections
>      Esp. if the congested router is using RED
> 3. rate-limiting per connection from the server      can be imposed  
> lower than your connection bandwidth
> 4. bandwidth allocation on congested links
>      Esp if the upstream router is using WFQ or DRR queuing, and  
> high capacity connections are severely limited

Thanks for these.

1.  Interleaving is possible with TCP, but for the most part TCP does  
not have round-trip delays except at the start and end.  Well, I  
guess some settings might.  There will be some interleaving from what  
I've seen.

2.  I don't know much about congestion at routers, but I agree with  
the affect of dropped packets.

3.  I think rate-limiting at source, if you are downloading from  
multiple servers, is the greatest factor.

4.  I claim ignorance.

Another factor might be the ability to give user feedback right away  
should there be a problem with any files.

I wonder if downloading multiple files might cause variations in  
transfer rates that confuse the optimization at servers and routers.

Just mumbling.

Dar Scott