Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

QoS on a link throttled upstream

Hello all,

I'm trying to setup some basic priority QoS on a FastEthernet link on my Cisco 2651 router (w/IOS 12.2). The problem is that the link is being throttled to 1.54mb/s upstream and so none of the packets ever stay in the output queue so QoS doesn't happen.

Is there a way to tell the router that this link cannot accept more than 1.54mb/s to get the queue to work? I've tried the rate-limit command on the interface, but that seems to use its own queue and packets won't get to the QoS queues.

Thanks for your help in advance!

2 REPLIES
New Member

Re: QoS on a link throttled upstream

It's better that you provide a configuration.

QoS will not kick in if there is no congestion.

Possible that your WAN interface is a T1 that cannot pass traffic more than 1.5M.

If that's not the case, First, you can change your load-interval on the interface to 30 sec on Fast Ethernet and check the input rate and output rate. That way you can see what's the real time input rate and if there is a bottleneck.

New Member

Re: QoS on a link throttled upstream

I have a connection to my ISP on Eth0/1 that is limited to 1.5mbits/s by the ISP. The router sees the interface as a full 100mbit/s FastEthernet, and is actually able to send to the ISP at that rate. The problem lies in that my ISP is dropping packets according to their own QoS, and not mine. Therefor the router doesn't see the congestion. I'm trying to figure out how to get the router to recognized the congestion, or somehow to force the congestion so I can control it.

I have tested the QoS on my router and verified that it is not kicking in. I did this by flooding the link with a lot of traffic (multiple HTTP downloads, streaming, Half-Life server, etc) and then running "sh int eth0/1" and watching the output queue (it never dropped a packet).

Here is my example config:

!

interface FastEthernet0/1

bandwidth 1504

ip address x.x.x.x 255.255.255.252

duplex auto

speed auto

priority-group 1

no cdp enable

!

priority-list 1 protocol ip low udp 27015

priority-list 1 protocol ip low tcp 6881

priority-list 1 protocol ip low tcp 6882

priority-list 1 protocol ip low tcp 6883

priority-list 1 protocol ip low tcp 6884

priority-list 1 protocol ip low tcp 6885

priority-list 1 protocol ip low tcp 6886

priority-list 1 protocol ip low tcp 6887

priority-list 1 protocol ip low tcp 6888

priority-list 1 protocol ip low tcp 6889

priority-list 1 queue-limit 20 40 100 80

92
Views
0
Helpful
2
Replies
CreatePlease to create content