Help for pinging Cisco WS-C2960S-24TS-L with heavy byte packet

Problem as below:
i use the following command.
ping -t -l 20000
then it gives me request time out.
but it ping smoothly with -l 17000

So, i need help for how to ping with heavy byte packet more than 20000 bytes before i can easy ping my cisco switch WS-C2960S-24TS-L . Thanks.


Are you having issues trying to register with our SIP accounts though?

The ping test is just to make sure your IP can connect to our SIP servers

If you can try with the PC client Blink on the same network like this post talks about it can help narrow down any issues