how to check QOS implementation???

You didn't specified whether you implemented QoS on Cisco router or switch, so I will assume that this is about router:

Bring the egress interface's load to it's max (or up to the traffic shaping value if any configured) and then execute IP SLA monitor probe... After that, remove QoS policy-map from that interface and then load the link again and measure parameters using Cisco IP SLA, so that you can simply compare IP SLA results you get with and without QoS.

For more info about Cisco IP SLA, please visit:

It's for IOS 12.4T and for earlier IOS releases (12.3T) you need to look for Cisco SAA probes, but rather then do that I recommend IOS upgrade, because I found my self hassling to find SAA documentation on Cisco site...

B.R. Igor

Just use iperf. It's free and runs on Windows and Unix machines. Use the -p option to run it on port 23 to simulate telnet traffic.