You can only reserve 75% of the total bandwidth. So bandwidth - 25% = reservable bandwidth.

So in your case, the total reservable bandwidth is 3840 - 1024 = 2816kbps

2816 is the total bandwidth for class-default. Use show policy-map to verify configuration.

-John

Prem Even i feel the same.

But is there any way to identify what traffic is actually flowing through the priority queue?

Say i generate a 512K traffic for priority queue will the other 512K be utilized for class default? if the traffic increases in priority queue will the class-default traffic be pusdhed to another queue?

John, i understand that the traffic will be reserved for only 75% but this is a default.

I have the max-reserve-bandwidth 100 command on the interface (not shown)

Narayan

Actually, i read two articles which is contradicting.

The first one said that LLQ is a strict priority. Even if the link is not congested. But the second article said that LLQ will just take effect if the link is congested.

Those are from Ciscopress books and both of them are CCIE authors. I don't know which one to believe. =)

-John

Hi Narayan

I still remember the tests which we carried in our backbone 2 years back with voice/ftp/icmp traffic to check the qos config behaviors.

We did see the behavior as normal and as mentioned in my first mail it doesn't strictly hold the bandwidth you configure in the priority queue..

regtds

Thanks Prem,

Is it possible to test whether i am getting the proper qos behavior for the strict priority?

Narayan

hi Narayan

Try connecting your laptop or pc onto the ethernet port of the routers on both the side and try to generate different traffic patterns like FTP/ICMP Ping.

You can classify icmp as prioritized traffic and make ftp as class default.

try to initiate different icmp sessions with different byte size and congest the link.

also try to do FTP between the PC so that you have both sort of traffic on the link.

By doing so you can verify the qos config behavior on your router.

also you can try to do a scenario of icmp only and ftp only.

regds