If you dont have a iperf on your server and you cannot install it for some reasons my iperf article will not help you to determine your throuphput. But you can check your bandwidth with some other tools. Most of them are standardtools on a server.

Alternative one: netcat With netcat you can do something similiar. First you need to open a listening port on one side, then you connect from another one.

# Serverside
[root@weichert ~] # netcat -vvnlp 12345 > /dev/null
listening on [any] 12345 ...
connect to [127.0.0.1] from (UNKNOWN) [127.0.0.1] 38340
sent 0, rcvd 149621964
# Clientside
time yes|netcat -v localhost 12345 > /dev/null
localhost [127.0.0.1] 12345 (?) open
real    0m41.912s
user    0m40.796s
sys     0m7.252s

Now you have to do some math, yeah i know - we all like that. Multiply the bytes rcvd by 8 to get total bits, then divide by the time: Result is 28559 MBit/s => 28Gbit/s

Alternative two: dd over ssh or netcat Lets have a look to dd. Here you will create a transfer over netcat oder with ssh to the target.

dd if=/dev/zero bs=1024 count=512 | netcat -v localhost 12345
# you will get something like
536870912 bytes (537 MB) copied, 3.42426 s, 182 MB/s
# with ssh
dd if=/dev/zero bs=1024 count=512 | ssh user@testhost.de 'cat /dev/null'
536870912 bytes (537 MB) copied, 3.42426 s, 182 MB/s

You have to multiply the 182MB/s by 8 to get Mbit/s

Have fun with playing around with that.