[c-nsp] CBWFQ with LLQ on Cisco 876

[Ivan Pepelnjak]

The problem you have is that there's no outbound queue forming on the Dialer
interface (PPPoE is too fast, as it goes over outside Ethernet).

http://blog.ioshints.info/2009/06/adsl-qos-basics.html

You have to apply shaping to force a queue to form. The shaping has to be
configured on the physical interface (outside Ethernet), not on the dialer
...

http://blog.ioshints.info/2009/07/not-all-interfaces-are-created-equal.html

 ... and then you'll hit another jitter problem (see comments in the
previous post)

I'm working on describing the whole problem (and the potential workarounds),
but it will take time.

Ivan
 
http://www.ioshints.info/about
http://blog.ioshints.info/

> -----Original Message-----
> From: Jean Gervers [mailto:jean at gervers.com] 
> Sent: Wednesday, July 08, 2009 12:31 AM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] CBWFQ with LLQ on Cisco 876
> 
> Hi,
> 
> does anybody know if the Cisco 876 is supporting LLQ on 
> Dialer Interfaces (PPPoE over ATM)?
> 
> The Packets are classified correctly by NBAR:
> 
>      Class-map: ef (match-all)
>        21 packets, 5124 bytes
>        5 minute offered rate 1000 bps, drop rate 0 bps
>        Match:  dscp ef (46)
>        Priority: 33% (304 kbps), burst bytes 7600, b/w exceed drops: 0
> 
> 
> and the dialer and corresponding virtual-access interface use 
> Class- based queueing as queueing strategy:
> 
> 
> Dialer1 is up, line protocol is up (spoofing)
>     Interface is bound to Vi1
>     Output queue: 0/1000/0 (size/max total/drops)
> 
> Virtual-Access1 is up, line protocol is up
>    Queueing strategy: Class-based queueing
> 
> 
> 
> But I still expiernce a huge Jitter/Delay when I start other high  
> volume TCP Connections.
> 
> 
> Thanks in advance,
> 
> Jean
> 
> 
>