05-02-2007 07:28 AM - last edited on 03-25-2019 03:15 PM by ciscomoderator
I am trying to design a QoS strategy for our WAN. The majority of our remote sites use 1024k links with Frame Relay encapsulation out to a service provider managed MPLS cloud.
The question I have is how QoS should be implemented on these links. In reading the Cisco QoS SRND Guide, it states that Frame Relay links at this rate fall under the Medium specification. According to the guide it says to set the following:
CIR: 95% of PVC contracted speed
Bc: CIR/100
Be: 0
minCIR: CIR
So the question is, since this is just an access link and not a traditional Frame Relay network, should I still implement shaping? And if so should it just be on the class-default?
Please Help! Thanks.
Solved! Go to Solution.
05-02-2007 08:14 AM
I think a nested policy should be the best option for you.
policy-map voice
class voice
priority percent 10
set ip dscp ef
compress header ip rtp
class signalling
bandwidth percent 1
class critical-data
bandwidth percent 34
class bulk
bandwidth percent 34
class class-default
fair-queue
policy-map CB-shaping
class class-default
shape average 102400 1280 0
service-policy voice
interface serial 0/0
service-policy output CB-shaping
HTH, rate if it does
Narayan
05-02-2007 07:53 AM
Friend,
Please elaborate what QoS are you planning to deploy in our network, Voice?
Shaping can severly affect voice performance
Also you need to check what QoS policies your service provider is running on his MPLS. Since the connections are not end-to-end deploying QoS at your end may not help once it goes into the MPLS cloud. They need to trust your markings
HTH, rate if it does
Narayan
05-02-2007 08:00 AM
I am planning on deploying the 5 class model in the following way:
1. Voice
10% Bandwidth Guarantee
RTP Compression
Low-Latency Queue
2. Call Signaling
1% Bandwidth Guarantee
3. Critical Data
Weighted Random Early Detection - DSCP Based
30% Bandwidth Guarantee
4. Bulk
34% Bandwidth Guarantee
5. Best Effort
Fair Queuing
My provider defines 5 traffic classes that these will map directly into.
05-02-2007 08:14 AM
I think a nested policy should be the best option for you.
policy-map voice
class voice
priority percent 10
set ip dscp ef
compress header ip rtp
class signalling
bandwidth percent 1
class critical-data
bandwidth percent 34
class bulk
bandwidth percent 34
class class-default
fair-queue
policy-map CB-shaping
class class-default
shape average 102400 1280 0
service-policy voice
interface serial 0/0
service-policy output CB-shaping
HTH, rate if it does
Narayan
05-02-2007 08:48 AM
Hi,
I think that the nestted method is the best but the only problem is that you can't set in 2nd level policy-map, and accordingly you can put the Classification and Marking policy map as in input policy map on the LAN interface.
You'll get this error:
'set' command is not supported in a 2nd level policymap
HTH, please do rate if it does help,
Mohammed Mahmoud.
05-02-2007 10:06 AM
As this is a frame relay interface, wouldn't I put this on the point to point serial subinterface under the frame-relay interface dlci x statemnt?
05-02-2007 10:13 AM
yes you are right
the policy needs to be applied under the subinterface carrying the DLCI information
HTH, rate if it does
Narayan
05-02-2007 10:15 AM
Hi,
It can be added under the PVC or the subinterface, it won't matter in your case, but the classification and marking one should be don on the Ethernet LAN interface.
HTH, please rate if it does help,
Mohammed Mahmoud.
05-02-2007 10:17 AM
OK. Thanks for the info. The real question here though is how to address the shaping issue. Since this is a frame relay link, shaping should be done per the QoS SRND Guide. Where would you put the shaping in the policy?
05-02-2007 10:22 AM
Hi,
You need only shaping, why would you require policing ?
BR,
Mohammed Mahmoud.
05-02-2007 10:23 AM
I didn't mention policing. I asked where in the QoS Policy would I put the shaping piece.
05-02-2007 10:32 AM
Hi,
Sorry :) The nestting example that Narayan has given above is perfect, where 2 policies are nestted in each other:
policy-map voice
class voice
priority percent 10
compress header ip rtp
class signalling
bandwidth percent 1
class critical-data
bandwidth percent 34
class bulk
bandwidth percent 34
class class-default
fair-queue
policy-map CB-shaping
class class-default
shape average 102400 1280 0
service-policy voice
interface serial 0/0
service-policy output CB-shaping
If you require classification and marking, you'll have to do it via a separate policy for the incoming traffic on the ethernet LAN.
HTH, please rate all helpful posts,
Mohammed Mahmoud.
05-02-2007 10:35 AM
OK. It is all clear now. Thanks guys!
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