05-03-2006 12:46 PM
Hi,
using the document "QoS Solutions for PPPoE and DSL Environments" as a reference I'm trying to implement Quality of Service for a DSL connection via the ATM interface on a 2821 router.
So I apply the service-policy under ATM VC configuration mode (PVC 8/35) and the command is accepted with no complaints, but when I do a show run, I realize the command is not there:
!
interface ATM0/0/0.1 point-to-point
pvc 8/35
encapsulation aal5snap
pppoe-client dial-pool-number 1
!
end
Any Idea why is this happening ?, we have version 12.3(14)T7. Is this the right way to configure QoS for DSL, or should I configure QoS on the dialer interface instead ? Any suggestions are welcome.
The document I checked can be found here.
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a00800b2d29.shtml
Regards.
05-03-2006 09:49 PM
hi
Can you user show policy-map interface command to check whether your service policy has been binded under the ATM interface ? can you also post the output for the command here ?
regds
05-04-2006 07:14 AM
Hi, of course,
whenever I try to configure a service-policy under pvc mode as recommended on the Cisco docs the command is accepted but it just doesn´t show up in the final config, also using the command you mentioned I can clearly see that the policy is not operational:
rtr#int atm0.1 point
rtr(config-subif)#pvc 8/35
rtr(config-if-atm-vc)#service-policy output QoS-Policy
rtr(config-if-atm-vc)#exit-vc
rtr#show policy-map interface
rtr#
This happens on a 2821 router with version 12.3(14)T7 but also happens on a 877 router
with version 12.3(8)YI2
Worth to mention is the fact that the command is accepted and seems to work Ok on the
877 router under atm main interface mode:
rtr#sh running-config interface atm 0
Building configuration...
Current configuration : 120 bytes
!
interface ATM0
no ip address
service-policy output QoS-Policy
no atm ilmi-keepalive
dsl operating-mode auto
end
I can clearly see that the policy is in effect:
rtr#show policy-map interface
ATM0
Service-policy output: QoS-Policy
Class-map: VoIP-RTP (match-any)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: protocol rtp audio
0 packets, 0 bytes
5 minute rate 0 bps
Match: access-group name VoIP-RTP
0 packets, 0 bytes
5 minute rate 0 bps
Queueing
Strict Priority
Output Queue: Conversation 40
Bandwidth 80 (%)
Bandwidth 102 (kbps) Burst 2550 (Bytes)
(pkts matched/bytes matched) 0/0
(total drops/bytes drops) 0/0
QoS Set
dscp ef
Packets marked 0
Class-map: VoIP-Control (match-any)
0 packets, 0 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: access-group name VoIP-Control
0 packets, 0 bytes
5 minute rate 0 bps
Queueing
Output Queue: Conversation 41
Bandwidth 5 (%)
Bandwidth 6 (kbps) Max Threshold 64 (packets)
(pkts matched/bytes matched) 0/0
(depth/total drops/no-buffer drops) 0/0/0
QoS Set
dscp af31
Packets marked 0
Class-map: class-default (match-any)
189 packets, 32032 bytes
5 minute offered rate 2000 bps, drop rate 0 bps
Match: any
Queueing
Flow Based Fair Queueing
Maximum Number of Hashed Queues 32
(total queued/total drops/no-buffer drops) 5/0/0
However the 2821 router oddly doest´n accept policies under atm main interface mode... (???)
rtr2#interface atm 0/0/0
rtr2#service-policy output QoS-Policy
CBWFQ : Not supported on this interface
Any ideas ?
Best regards.
05-04-2006 01:39 PM
I believe it is very important to apply the service policy under/after the VCI/VPI because you want it applied to the individual VC not the physical interface.
Sometimes when a virtual-template is created you have to configure it there.
Rate if this helps.
Mike
05-08-2006 02:45 PM
You cant apply a QoS policy to an ATM PVC without traffic shaping configured. Best (and most often configured) ATM traffic shaping is vbr-nrt. Basically you plug in your upload bandwidth and it'll traffic-shape you to that rate. More importantly, it helps the QoS schedule allocate bandwidth for the various classes.
Do the following:
interface atm0/0/0.1
pvc 8/35
vbr-nrt 768 768
tx-ring-limit 5
service-policy output
Once you exit out of this, the command should have stuck, and you'll be able to issue a 'show policy-map interface atm0/0/0.1'.
If you're upload speed isn't 768k, change the vbr-nrt statement to whatever the speed is, in kbps.
You may also notice I put in a tx-ring-limit command. This is needed to create backpressure from the module to the router, telling it to use the QoS classes you have configured.
05-09-2006 06:06 AM
Do you have any links that might help explain this.
Is this the case for all ATM interfaces?
Thanks,
Mike
05-10-2006 10:56 AM
Yeah, it applies to all ATM. Check this out:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1830/products_feature_guide09186a0080087a82.html
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