LAN test for 10/100 MB/s command line code

I work in the VoIP phone field and I'm trying to create a batch file to find out whether or not there is a device on the network that is only 10MB/s rated.

I should be able to ping all of the IP address and find the millisecond speed to get an idea of it being 10/100 or 100/1000 right?

I'm assuming it's the ping command - - I'd like to use a command like ARP -a (with associated speeds)

Maybe a broadcast ping and results? (Windows OS)

• many thanks,

George