Callmanager QoS for Clustering over the IP WAN

[Brian Carscadden]

Looking for a good QoS policy to apply on WAN links for CM 4.1(3) SR1 Publisher/Subscriber communication. I recall only that bandwidth required is about 982kbs. I'm looking for a specific policy for standard CM services (all but Messaging Interface, Certificate Authority Proxy)

[mheusinger]

Hi,

the most simle approach would be to specify source and destination IPs of the two CM f.e. with an access list and use CBWFQ to priotitize the traffic. in case you want to use marking pick a so far unused IP precedence (or DSCP) value (f.e. 2).

Example:

class CMtraffic

match ip address 101

policy-map OUT

class CMtraffic

bandwidth 1000

set ip precedence 2

class class-default

fair-queue

random-detect

interface Serial0

service-policy output OUT

access-list 101 permit ip host host

The traffic between VoIP devices and CM would not be prioritized in this example. For you voip calls and voip signaling you should plan for the nessessary resources as well. But I assume you are aware of it and took care about it.

Hope this helps

Martin

[Brian Carscadden]

It was my 'plan b' to use a simple host ACL, and is likely the route I'll take. Yes, we have an existing ACL/QoS Policy to handle all control and rtp traffic.

Thanks for your input Martin.

Regards

[mheusinger]

Hi,

just another document I just stumbled into might allow for better tuning of your class-map:

"Cisco CallManager 4.1 TCP and UDP Port Usage"

http://www.cisco.com/application/pdf/en/us/guest/products/ps5820/c1693/ccmigration_09186a0080536eae.pdf

Did this help? Then please rate

Martin

[jesseramos]

Will this work over a T1? I have a customer that wants to move their Sub to a remote site connected via T1. I currently have voice traffic prioritized with 768kb as shown here:

class-map match-any VOICE

match ip dscp ef

match ip dscp af31

!

!

policy-map VOICE

class VOICE

priority 768

!

!

When I tried to add "bandwidth 1000" for the intracluster traffic, I got a message saying I only have 384kb available.

I also tried bringing the priority for voice traffic down to 512, but still not enough for the 928 kb.

What would be the best solution for this scenario?

Thanks,

Jesse