[c-nsp] LLQ + MLPPPoE -> ?

David Freedman david.freedman at uk.clara.net
Wed Aug 27 20:42:22 EDT 2008


Yes, it seems to be working when applied to the dialer (i.e , the class is seeing traffic matched
and queued into the correct queue) but when the bundle contains more than one member, the latency and jitter increases when there is congestion, which leads me to think that either:

1. The queuing has stopped working
or
2. This is a side effect of having more than one member in the bundle in this configuration.

We've taken all the usual precautions (i.e disabling LFI and permitting link re-ordering on the bundle) but the quality still degrades under load when we add another member. 

Interestingly, when we create a multilink virtual interface (int mu1) and do straight unauthenticated mlpppoa with the same LLQ policy, it works great.



------------------------------------------------
David Freedman
Group Network Engineering 
Claranet Limited
http://www.clara.net



-----Original Message-----
From: Ben Steele [mailto:ben.steele at internode.on.net]
Sent: Thu 8/28/2008 01:26
To: David Freedman; cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] LLQ + MLPPPoE -> ?
 
That example is using a virtual-template, not a dialer, there used to be an
issue some time ago where if you didn't run MLPPP on your dialer your
QoS(CBWFQ) wouldn't work properly as it required an MLP Bundle to attach to,
a work around for this was using virtual-template and ATM int for QoS.

If you are using MLPPP as it appears you are by your config, then all that's
needed in your ATM is to specify the correct service class (ie cbr/ubr/vbr)
and speed, the tx-ring-limit will make sure you don't buffer up any packets
in the ATM interface then all your magic should be done on the dialer with
your service-policy.

Make sure you set the bandwidth appropriately (ie subtract 15% for atm cell
tax overhead) and you should see it all come to life through your MLP
Bundle.

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of David Freedman
Sent: Thursday, 28 August 2008 12:13 AM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] LLQ + MLPPPoE -> ?

>Remove the service policy from your ATM int's and just leave it on your
>Dialer, then do a "sh users" and you should see an interface listed as the
>MLP Bundle, this is the one you want to be watching, if for example it is
>Vi4 then do a "sh policy-map int vi4"

I was following the advice at
http://www.cisco.com/en/US/tech/tk543/tk544/technologies_tech_note09186a0080
094ad2.shtml
which states:

". When you use a combination of Class-based Marking or Class- based
Policing and Class-based Queuing, the order of operations is this:

   1.

      The service-policy command configured on the Virtual-Template
interface marks or polices the packets.
   2.

      The service-policy command on the ATM PVC queues the packets
"

Is this not correct? 



------------------------------------------------
David Freedman
Group Network Engineering 
Claranet Limited
http://www.clara.net

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