[asterisk-users] Two way bandwidth test

[Gordon Henderson]

On Tue, 15 Jul 2008, Matt Darnell wrote:

> Does anyone know of a bandwidth test that tests the upload with the download?
>
> All of the ones I can find will test the upload then the download.
>
> I from experience I have found that a 3M/768K DSL can only do about
> 256K/256K simultaneously.

You have a sucky ISP or router.

> The only way I have of testing it is with FTP uploads and downloads or
> P2P sharing.
>
> I would like something more formal that would keep the upload speed
> the same as the download.  VoIP as you know is symmetric.
>
> The one VoIP test I find doesn't tell you how many calls you can
> handle, just if it is VoIP ready.

iperf

You run a "server" on one site, and a "client" on the other.

So on site a:

   iperf -s -u

then on the other site:

   iperf -c ip.of.site.a  -u -b 80K -l 160

That's a one-way test from site B to site A. To do a test both ways, one 
at a time:

   iperf -c ip.of.site.a  -u -b 80K -l 160 -r

To test both ways at the same time:

   iperf -c ip.of.site.a  -u -b 80K -l 160 -d

The -b parameter is the bandwidth to use, so start at 80K (one SIP link) 
and go up from there. The -l is the packet length - VoIP packets are 
typically 160 bytes.

The one thing it can't do it send the packets in a timed manner - 
simulating an RTP stream... ie. it needs a "packets per second" parameter 
rather than a bandwidth parameter, but this is usually good enough to find 
gross problems with links, I've found.

Gordon