QoS on saturated WAN link

[Mooseloose]

I'm looking to Qos an 800Mb Layer 2 link, to our DR site, from a 6807-XL with VS-SUP2T-10G Supervisor.

Dedupe of our backup traffic is killing this link. I'm not 100% sure on how to go about this, I thought this could do the trick but I'm not really 100% up on QoS, so any feedback would be very much appreciated:

ip access-list extended NETBACKUP_QOS
permit ip any host x.x.x.x (dest dedupe appliance)

class-map CM_NETBACKUP match-any
match access-group name NETBACKUP_QOS

policy-map PM_NETBACKUP
 class CM_NETBACKUP
  bandwidth percent 60
 class class-default
  fair-queue

interface x/x/x
 service-policy output PM_NETBACKUP

I did also think that shaping the link to 800Mb would be a good idea as the circuit is 800Mb and the Switch interface 1Gb.

policy-map PM_NETBACKUP
 class CM_NETBACKUP
  bandwidth percent 60
 class class-default
  fair-queue

policy-map PM_PARENT_SHAPE
 class class-default
  shape average 800000000
   service-policy PM_NETBACKUP

interface x/x/x
 service-policy output PM_PARENT_SHAPE

Are there any advantages/disadvantages to doing one over the other?

At some point this year there may also be voice traffic traversing this link so I also thought, while I'm at it, I could get the link ready for voice traffic:

class-map CM_VOICE match-any
 match dscp ef

class-map CM_VOICE_SIG match-any
 match dscp af31

policy-map PM_QoS
 class CM_VOICE
  priority percent 10

 class CM_VOICE_SIG
  priority percent 5
 class CM_NETBACKUP
  bandwidth percent 60
 class class-default
  fair-queue

interface x/x/x
 service-policy output PM_QoS

or with shaping?

policy-map PM_QoS
 class CM_VOICE
  priority percent 10
 class CM_VOICE_SIG
  priority percent 5
 class CM_NETBACKUP
  bandwidth percent 60
 class class-default
  fair-queue

policy-map PM_PARENT_SHAPE
 class class-default
  shape average 800000000
   service-policy PM_QoS

interface x/x/x
 service-policy output PM_PARENT_SHAPE

Am I barking up the wrong tree with these configurations?
Thanks,
Jim.

[Joseph W. Doherty]

"I did also think that shaping the link to 800Mb would be a good idea as the circuit is 800Mb and the Switch interface 1Gb."

Yes, that's what you want to do.

"Am I barking up the wrong tree with these configurations?"

You might be. Generally shapers were not supported on the 6500 series without a card like the FlexWAN. I don't recall (?) the 6807 with a sup2T adding shaper support.

If it doesn't support shaping, your choices would be to upgrade the link to full gig or use another device that can shape for the 800 Mbps (e.g. an upgraded 4451 or low end ASR 1K).

BTW, on your policy, I would suggest only allocating 1 percent for your backup traffic and if you're going to place VoIP bearer and signalling in LLQ, you might just use one class and set it for the combined bandwidth. I would also suggest you use a bandwidth allocation for class-default.

[Mooseloose]

Thanks for taking the time to respond to my query.

I tried configuring the shaping policy on our 6807and it took the commands, so I'm assuming it will shape, if not then I'll ask our provider about upgrading the link to 1Gb as we could do with the extra capacity anyway.

Taking on board your advice, I will configure this:

class-map CM_VOICE match-any
 match dscp ef
 match dscp af31

policy-map PM_QoS
 class CM_VOICE
  priority percent 15
 class CM_NETBACKUP
  bandwidth percent 1
 class class-default
  bandwidth percent 25
  fair-queue

[Mooseloose]

The more I look at this the more I'm unsure about the bandwidth I've assigned to class-default. 

Should I be assigning the remainder to it? 

policy-map PM_QoS
 class CM_VOICE
  priority percent 15
 class CM_NETBACKUP
  bandwidth percent 1
 class class-default
  bandwidth percent 84 (instead of 15?)
  fair-queue

Again, thanks! 

[Joseph W. Doherty]

It depends on the allocation ratio you desire between the two classes. With just the two classes, your examples with be 1:25 or 1:84.

If your non-backup traffic doesn't routinely fill the link 1:84 should be fine.