07-30-2008 11:49 AM - edited 03-03-2019 10:57 PM
Hello,
I am attempting to apply a simple CBWFQ/LLQ policy for voice traffic over an ATM UBR configured as a subinterface. When I apply the service-policy to the PVC on the subinterface it doesn't stick. A warning is logged saying that there is no available bandwidth to reserve. From other reading it seems this is directly related to PVC being configured as a UBR. Does this mean no QoS can be applied to a UBR? If not, then how must this be done?
Here is a sanitized snippet of the config in question:
policy-map QoS-WAN
class VoIP-Voice
priority 768
class VoIP-Control
bandwidth 16
class Critical
bandwidth 256
class class-default
fair-queue
!
interface ATMx/x.x point-to-point
bandwidth 10000
ip address x.x.x.1 255.255.255.252
pvc 1/x
protocol ip x.x.x.2 broadcast
ubr 10000
encapsulation aal5snap
!
!
Thanks in advance,
Jim
07-30-2008 12:36 PM
The policy is accepted on an ATM VC since the VC supports native ATM-layer shaping via the vbr-nrt, vbr-rt, cbr or abr commands.
I thinks the service-policy on ubr vc not works..
but try..
(config)#int atm x/x.x
config-subif)#pvc x/x
(config-if-atm-vc)#exit
(config-subif)#service-policy output QoS-WAN
--
Raul
07-30-2008 12:46 PM
Raul,
Thanks for the response. I cannot apply the service-policy to the subinterface directly. When attempted I receive the following:
CBWFQ : Not supported on subinterfaces
To clarify, when I apply the service-policy to the PVC it accepts the command initially but reports the following when exiting config mode.
Jul 30 14:43:49.433: I/f ATMx/x.x VC x/x class VoIP-Voice requested bandwidth 0 (kbps), available
only 0 (kbps)
Jim
07-31-2008 08:00 AM
Try configuring Class-Based shaping..
policy-map TEST
class dscp46
shape average 30000 10000
class web
shape average 20000 15440
!
(config)#int atm x/x.x
config-subif)#pvc x/x
(config-if-atm-vc)#exit
(config-subif)#service-policy output TEST
--
Raul
07-31-2008 09:35 AM
Raul,
I configured the following:
class-map match-all GENERAL_TRAFFIC
match ip dscp default
policy-map SHAPE-WAN-ATM
class GENERAL_TRAFFIC
shape average 9000000 256000
When I applied it to the ATM subinterface I recieved the following:
GTS : Not supported on this interface
I tried applying it to the PVC as well and it initially took but reported the following when exiting config mode:
Jul 31 11:29:51.750: GTS : Not supported over ATM VCs
Any other thoughts?
08-02-2008 12:49 PM
Hello Jim,
try to apply the command to the physical interface
What happens ?
May you tell what router model, ATM interface and IOS version you are using
Hope to help
Giuseppe
08-03-2008 08:54 PM
Giuseppe,
Correct me if I am wrong, but I wouldn't want to apply it to the physical interface becase of the other ~20 sub interfaces that are not UBR's and need/have thier own QoS service-policy.
I am using a 3745 with 12.4(15)T6 Advanced IP Services.
Thanks,
Jim
08-03-2008 10:09 PM
Hello Jim,
you are right: you are using a powerful router but of course you cannot apply the service-policy on the physical interface if you have other 20 PVCs and subifs working.
I just wanted to understand the scenario.
If you have been able to apply service-policy on other ATM subinterfaces and/or PVCs that are not using UBR, the only way is to change the ATM Class of service of this PVC, because the IOS checks if the PVC has some guaranteed resources or not (like it happens for UBR).
Try to negotiate with the service provider a change in the ATM CoS of the PVC or configure it as an ABR with low parameters just to be able to apply the service-policy (I'm not sure that this is without drawbacks so verify if there are )
Hope to help
Giuseppe
08-04-2008 07:20 AM
Giuseppe,
Thanks for the reply. That was going to be my next step. Thanks for verifying this.
Jim
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