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LLQ with EZVPN over DSL (PPPoA) with Dialer Interface

ccpagel
Level 1
Level 1

Hi,

I need to configure QoS for VoIP on a DSL router using PPPoA. The VoIP traffic is going over the EZVPN tunnel.

My problem is that a 'show policy-map interface dialer0' shows packets/bytes but I never get any hits in packets matched/bytes matched fields.

I've even removed EZVPN and applied test policies to internet traffic but still get no hits. So my access-list and the classes are being matched correctly it just that queuing does not seem to be working. I searched CCO and I can't find any examples of LLQ with PPPoA so it may not be supported. Any ideas anyone?

Thanks,

Chris

Service-policy output: Pol-OutClassify

Class-map: Node4-EZVPN (match-all)

483 packets, 31878 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: ip dscp ef (46)

Queueing

Strict Priority

Output Queue: Conversation 136

Bandwidth 128 (kbps) Burst 3200 (Bytes)

(pkts matched/bytes matched) 0/0

(total drops/bytes drops) 0/0

Class-map: test (match-any)

2835 packets, 187110 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: access-group 115

2835 packets, 187110 bytes

30 second rate 0 bps

Queueing

Output Queue: Conversation 137

Bandwidth 10 (%)

Class-map: class-default (match-any)

342 packets, 280978 bytes

30 second offered rate 0 bps, drop rate 0 bps

Match: any

Queueing

Flow Based Fair Queueing

Maximum Number of Hashed Queues 128

(total queued/total drops/no-buffer drops) 0/0/0

QoS Set

dscp default

Packets marked 349

2 Replies 2

mheusinger
Level 10
Level 10

Hello,

are you sure, that the VoIP traffic is marked properly as ef? Also with EzVPN have you configured qos pre-classify on the tunnel?

Can you enable nbar protocol discovery at the input interface to check the protocols and existance of VoIP traffic.

Also use "auto qos voip" as a start. The latter should reconfigure your router preperly for VoIP.

Hope this helps! Please rate all posts.

Regards, Martin

qos pre-classify isn't available with EZVPN. It isn't required as the DSCP marking are automatically copied from the original IP packet header to the IPSec packet header.

I've actually resolved this now.

If you read the SRND for QoS it discusses QoS over broadband (www.cisco.com/go/srnd). The problem was that the service policy must be applied to the ATM sub-interface and not the dialler interface. Also you need to specify that the sub-interface is not UBR by specifying VRT-NRT, VBR-RT or CBR parameters as below.

interface ATM0/0/0

bandwidth 256

no ip address

no ip redirects

no ip unreachables

no ip proxy-arp

ip route-cache flow

no atm ilmi-keepalive

dsl operating-mode auto

pvc 0/38

vbr-nrt 288 288

encapsulation aal5mux ppp dialer

dialer pool-member 1

service-policy output WAN-QOS

!

With this configuration a 'show policy-map int atm0/0/0' now shows packets matched and bytes matched.

Regards,

Chris

Review Cisco Networking products for a $25 gift card