How can I output only the average bandwidth of 5 parallel connection using Iperf3?

Question

I have the following line in a shell script:

bandwidthOutput=$(iperf3 -c 127.0.0.1 -R --parallel 5 --format M --version4)

And I want to only save the average bandwidth (Upload speed) in $bandwidthOutput. How do I do this?

I tried using awk, but I could not find any information of where in the Output this information could even be found.

Edit: From my understanding my line in the shell script should be able to output this data in the last line, but I am unsure.
So I actually have two Questions:

1. Where do I find the average bandwidth with Iperf3? I think it is in the last line [SUM]
2. How do I then Output only that data with awk?
   -I tried Outputting the 5th Element of the last line, but this looks different from the Output I see in the window of my server (run with iperf3 -s)

Answer 1

Your question is really unclear.

You want something to be done with awk,

and you even specify what (save the average bandwith),

But this makes everything unclear: "I could not find any information of where in the Output this information could even be found."

If you do not know if the information you need is in the output, how would you then use awk to find this information?

Probably you need one of the figures in these 2 lines:

iperf3 -c somehost -R --parallel 5 --format M --version4 | grep 'SUM' | tail -2

or

iperf3 -c somehost -R --parallel 5 --format M --version4 | tail -4 | head -2

The output is something like this:

[SUM]   0.00-10.05  sec  1.10 GBytes   112 MBytes/sec                  sender
[SUM]   0.00-10.00  sec  1.09 GBytes   112 MBytes/sec                  receiver

Answer 2

You can use iperf 2.0.14 and the --sum-only option

[rjmcmahon@localhost iperf2-code]$ src/iperf -c 192.168.1.10 -P 5 --sum-only -i 1
------------------------------------------------------------
Client connecting to 192.168.1.10, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[SUM-cnt] Interval       Transfer     Bandwidth
[SUM-5] 0.00-1.00 sec  1.11 GBytes  9.53 Gbits/sec
[SUM-5] 1.00-2.00 sec  1.09 GBytes  9.40 Gbits/sec
[SUM-5] 2.00-3.00 sec  1.10 GBytes  9.43 Gbits/sec
[SUM-5] 3.00-4.00 sec  1.09 GBytes  9.40 Gbits/sec
[SUM-5] 4.00-5.00 sec  1.10 GBytes  9.42 Gbits/sec
[SUM-5] 5.00-6.00 sec  1.10 GBytes  9.42 Gbits/sec
[SUM-5] 6.00-7.00 sec  1.09 GBytes  9.40 Gbits/sec
[SUM-5] 7.00-8.00 sec  1.10 GBytes  9.43 Gbits/sec
[SUM-5] 8.00-9.00 sec  1.09 GBytes  9.41 Gbits/sec
[SUM-5] 9.00-10.00 sec  1.10 GBytes  9.41 Gbits/sec
[SUM-5] 0.00-10.00 sec  11.0 GBytes  9.43 Gbits/sec

Bob