C'est peut être un marteau pour écraser une mouche, mais je crois que nufw sait faire ça.

Pour un soft particulier.

trickle - a lightweight userspace bandwidth shaper

trickle [-h ] [-v ] [-V ] [-s ] [-d rate ] [-u rate ] [-w length ] [-t time ] [-l length ] [-n path ] command ...

DESCRIPTION

trickle is a userspace bandwidth manager. Currently, trickle supports the shaping of any SOCK_STREAM (see socket(2)) connection established via the socket(2) interface. Furthermore, trickle will not work with statically linked executables, nor with setuid(2) executables. trickle is highly configurable; download and upload rates can be set separately, or in an aggregate fashion.

The options are as follows:

-h
Displays help.
-v
Increases the verbosity level (can be specified multiple times).
-V
Prints version.
-s
Runs trickle in standalone mode, independent of trickled(8).
-d rate
Limit the download bandwidth consumption to rate KB/s.
-u rate
Limit the upload bandwidth consumption to rate KB/s.
-w length
Set peak detection window size to length KB. This determines how aggressive trickle is at eliminating bandwidth consumption pea ks. Lower values will be more aggressive, but may also result in over shaping. The default value (512 KB) is usually sufficient.
-t seconds
Set smoothing time to seconds s. The smoothing time determines with what intervals trickle will try to let the application transcieve data. Smaller values will result in a more continuous (smooth) session, while larger values may produce bursts in the sending and receiving data. Smaller values (0.1 - 1 s) are ideal for interactive applications while slightly larger values (1 - 10 s) are better for applications that need bulk transfer.
-l length
Set smoothing length to length KB. The smoothing length is a fallback of the smoothing time. If trickle cannot meet the requested smoothing time, it will instead fall back on sending length KB of data. The default value is 10 KB.
-n path
Use trickled(8) socket path to communicate with trickled(8). By default, /tmp/.trickled.sock is used.

EXAMPLES


trickle -u 10 -d 20 ncftp

Launch ncftp(1) limiting its upload capacity to 10 KB/s, and download capacity at 20 KB/s.

SEE ALSO


trickled(8), syslog(3), socket(2), netintro(4)

AUTHORS


trickle has been developed by Marius Aamodt E riksen Aq marius@monkey.org .

BUGS


Does not support executables utilizing kqueue(2). Does not support statically linked executables.

Ok.
Je vous remercie. Je vais regarder ces deux programmes.