QoS on a DSL Router Where to apply Serivce Policy

[bill.morton]

I have an 1841 ISR Router with a WIC-1ADSL card for my WAN connectivity. I have an RFC 1483 with the ATM terminating at my router:

Running config:

interface ATM0/0/0

no ip address

no ip redirects

no ip proxy-arp

ip route-cache flow

no atm ilmi-keepalive

dsl operating-mode auto

dsl enable-training-log

!

interface ATM0/0/0.1 point-to-point

description $FW_OUTSIDE$

ip address 209.x.x.x 255.255.255.248

ip access-group OutsideACL in

ip verify unicast reverse-path

no ip redirects

no ip proxy-arp

ip nbar protocol-discovery

ip nat outside

ip inspect OUTBOUND out

ip ips sdm_ips_rule in

ip virtual-reassembly

atm route-bridged ip

pvc 0/32

!

My problem is trying to apply a QoS policy. If I try to apply the policy to the ATM subinterface (with the IP address) I get:

BorderRouter(config-subif)#service-policy output ShapeOutbound

CBWFQ : Not supported on subinterfaces

If I try to apply the service policy on the VC 0/32, the router hangs for about 20 seconds, and then never applies the service policy.

BorderRouter#sh policy-map interface atM 0/0/0.1 vc 0/32

Service policy is not configured on VC 0/32

Is there any way to apply an outbound service policy map on a DSL interface? I have a Dot1q trunk on my Ethernet interface (to my switch), so I cant apply it there.

Any other ideas, or something I am missing? Oh and: 124-19.bin is my current IOS.

[Joseph W. Doherty]

Since you didn't post either your policy or note your PVC bandwidth, can't say whether this is the issue, but I've encountered "silent drops" of service policies if the interface's bandwidth didn't support the bandwidth requested by the policy. (BTW: The "silent drops" gave no indication at the command line, but I recall there was a syslog entry made.)

[bill.morton]

Ok, some replies:

CEF is enabled.

NBAR is enabled (requires CEF)

I set the bandwidth on both ATM0/0/0 & 0/0/0.1 to 864, same message about CBWFQ not supported.

PVC does not support bandwidth command.

When I apply the command I get this error thrown in the syslog: 001606: May 1 09:25:41.403 CDT: I/f ATM0/0/0.1 VC 0/32 class Bulk requested bandwidth 0 (kbps), available only 0 (kbps)

The simple service policy I am trying out:

class-map match-any Bulk

match protocol edonkey

match protocol gnutella

match protocol fasttrack

match protocol kazaa2

!

!

policy-map ShapeOutbound

class Bulk

bandwidth percent 20

[t814687 · Accepted solution]

Hi Bill,

When applying CBWFQ policy to a vc you have to make sure you configured COS for ATM vc as VBR or ABR otherwise the policy can not be applied per VC.

Please refer to this guide when configuring QoS for IP to ATM:

http://www.cisco.com/en/US/docs/ios/qos/configuration/guide/ip_to_atm_cos.html#wp1001308

note this statement in the VC configurations in the document:

vbr-nrt 5000 3000 500

-serg

[bill.morton]

Brilliant!

This has been an unresolved problem for me for a long time =)points will be awarded.

Now one last question, if you have an asynchronous connection like mine, 1500 down, 864 up; is there any way to set the downstream speed higher (default will only let you to up to the smaller number) or should I just over-commit my policy maps?

[t814687]

Well, I thought I already earned some points ;) just kidding...

As far as I remember you can not oversubscribe if you use vbr-nrt, the router will complain I think.

You can play with other settings and use ubr which will correspond the downstream speed on the pvc. Read through the doc on use ubr.

Another thing is that DSL speed is dynamic depends a lot on a quality of your last mile copper pair and sometimes the rate can go down so well your setting for vbr or ubr on the pvc. Hope it makes sense what I'm saying....

-serg

[bill.morton]

Sure does, Thanks Serg & everyone! Next book I am going to read is QoS =)

[t814687]

hi, did you enable cef ?

It's required for QoS config.

-serg