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

Sat May 30 11:01:06 UTC 2020
hw <hw at gc-24.de>

On Saturday, May 30, 2020 12:46:02 PM CEST you wrote:
> On 30/05/2020 12:32, hw at gc-24.de wrote:
> Hi hw,
> > 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.
> You can't read from /dev/null. You get nothing from it. You're better
> off using /dev/random, for example. That will give you a continuous
> stream of random bytes.

Oh, ok, yes, of course, that makes sense :)

> However, that's not the focus of this. You want a sustain a stream of
> packets between two hosts. You're better off using UDP for this. And a
> good tool for generating such packets would be "iperf". It can measure
> bandwidth between two nodes more accurately.

Hm, iperf came to mind, and I looked at the manpage again.  It doesn't seem to 
have a way to transmit/receive indefinitely, though it seems it has basically 
everything I'm looking for except for unlimited transfers.  I'll try it out; I 
can always look at the source code and try to do about something about the 
limit if I need to.