03-19-2011 12:31 PM - edited 03-16-2019 04:02 AM
This might be more of a question for QOS, but it does have to do with voice, so I'll give it a shot here. We're a callmanager 7 environment using skinny and mcgp.
I have a 4x T1 MLPPP WAN solution at my main site, and in case I decide to increase my bandwidth, I want to be able to keep my same bandwidth allocations for tiered voice and data.
My WAN provider will automatically set the QOS on the links the way I have it set up, but if packets are to drop, I'd rather them drop at my router than against the wan where I have zero visibility.
I want my allocations to be in 4 tiers. Top Tier gets 40%, and the other three tiers get 20% each Class1 is for voice, Class2 is for VOIP Control/MCGP/Skinny, Class3 and Default are for remaining traffic.
I did some research, and tried this config. However, what I got on the Class3 was an error that after setting priority percent 40 and 20 on the upper two classes, that there was only 15% of bandwidth remaining. Last I checked, 40 and 20 equaled 60, not 85. There must be something I'm missing.
Here's the policy map I'm wanting to set for my WAN traffic.
policy-map DV-L3-OUT
class Class1
priority percent 40
set dscp 46
class Class2
priority percent 20
set dscp 32
class Class3
priority percent 20
class class-default
fair-queue
I would appreciate any feedback that anyone might be able to offer.
James
03-19-2011 02:11 PM
You don't really want to use "priority percent X" for anything except voice bearer traffic. Use "bandwith percent X" for your remaining guaranteed queues, including voice signaling traffic.
03-19-2011 04:04 PM
Hi,
The default maximum reservable bandwidth value of 75 percent is designed to leave sufficient bandwidth for overhead traffic, such as routing protocol updates and Layer 2 keepalives. It also covers Layer 2 overhead for packets matching defined traffic classes or the class-default class. You now can increase the maximum reservable bandwidth value on ATM PVCs using the max-reserved-bandwidth command.
Thats exactly why the third priority command threw an error.
http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_note09186a0080103eae.shtml
Here's a mind map which I personally like
http://cciev.wordpress.com/2006/05/25/qos-for-wan/
http://www.mindomo.com/view?m=1aa303cf33751870d7cba78aef9e0386 (Thanks to Arden Packeer)
You should go thru the above doc. ... or just use AUTO QOS
/divin
PS:Rate only useful posts.!
03-19-2011 04:07 PM
Sample Config
int se0/0/0
bandwidth X
max-reservable-bandwidth 80
policy-map DV-L3-OUT
class Class1
priority percent 40
set dscp 46
class Class2
bandwidth percent 20
set dscp 32
class Class3
bandwidth percent 20
class class-default
fair-queue
HTH
/divin
PS: Rate ONLY useful posts!
03-21-2011 04:12 PM
Mark this as resolved if you have no more questions! I see redunant posts in to section on CSC
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