[Info-vax] Slow FTP transfer Linux -> VMS

[Richard Whalen]

I had a customer report some transfer rate problems with MultiNet recently 
and upon investigation found that the cause of the problem was due to a 
packet burst limit (4 packets) that is part of the congestion control 
algorithm.  MultiNet allowed the customer to change the congestion control 
algorithm that was being used and that resolved the transfer rate problem. 
In my research on this burst limit and the congestion control algorithm I 
found that many implementations of Unix have a similar limit and that some 
had found better throughput with a burst limit of 8.

Raising the burst limit does has some possible consequences - a greater load 
is imposed on any intermediate systems and the end system before any 
acknowledgements can be processed to cut back on the number of packets. 
Also if an intermediate packet gets dropped the recovery cost could be 
higher.


"Robin Schipper" <"thespriteman <remove_this> wrote in message 
news:4a9780ef$0$196$e4fe514c at news.xs4all.nl...
> Hi,
>
> when i try to put a big file (lets say 100 Mb) from a Linux system trugh 
> FTP on a VMS system, the max speed is 1,5 MB/s
> when i try to put the same file from another VMS system (on the same 
> network) to the VMS box the speed is about 10MB/s (it is a 100Mb network)
>
> does anyone know why the linux box doesn't speed up, and how to solve it?
>
> With Regards,
>
> Robin Schipper