[CentOS] looking for ideas about how to create a constant data stream

Sat May 30 10:55:16 UTC 2020
Yamaban <foerster at lisas.de>

On Sat, 30 May 2020 12:32, hw at ... wrote:

> Hi,
> I'm looking for a good way to create a constant data stream that will occupy a
> bandwidth of about 2--5Mbit/sec between two remote hosts over the internet.  I
> have full access to the hosts involved.
> My first attempt to use scp to copy data from /dev/null on host A to /dev/null
> on host B, but scp says '/dev/null: not a regular file'.  If something like
> that would work, I would be able to limit the bandwidth of this transfer in
> the router(s) involved so that it won't occupy all the bandwidth.
> Of course, it would be better if I could limit the bandwidth on the sending
> side rather than dropping packages. I could probably write some program to do
> that, but since I have never programmed such a kind of network application, it
> would be rather time consuming.  Maybe there's already a kind of tool around
> that can do this.
> I need this to work around whatever settings my ISP has made 3 days ago that
> block my VPN connection so that I effectively can't reasonably work anymore.
> I do know what the problem with the connection is and that occupying some
> bandwidth would unblock the VPN; only there doesn't seem to be anything else I
> could about it.

Hmm, last time I had such issues (~10 years ago), I had a ssh-server on
one side running, and used scp from the other side:
  scp -l [banwidth in Kbit/sec] /dev/zero [user at remote host]:/dev/null

For me at the time 150 kbit/sec was enough to keep my channel open.

Others used netcat (nc) in a script to get the similar results
  (feeding it "lines" at a certain rate to limit the traffic)

Have a nice weekend.
  - Yamaban