Bandwidht reservation for Video/Voice Traffic

s.aliyarukunju · ‎05-05-2012

Dear Experts,

In my organisation , i have a video conferencing unit that is natted with public IP for remote party to dial-in by IP. Now the new requirment is i need to reserve 6 Mbps of bandwidth for video/voice traffic (in/out) out of my total 32 Mbps internet bandwidth.Below is the network scenario.

We have two location ( Head quarter & Branch location) . The branch location is connected to Head Quarter over the MPLS connection of 100 Mbps.

The head quater is connected with internet connection of 32 Mbps and the branch location is accessing the internet service over MPLS WAN link. The video conferencing unit is connected on Branch location only.

WAN LINK (100Mbps) 32Mbps internet

[Video conferencing Unit]------[BR-L2Switch]----[BR-L3Switch]===================[HQ-L3Switch]----[HQ--ASA]-----[HQ-Router]------------(((( ISP )))))

Here BR denotes Branch location and HQ denotes Head quarter.

The Natting for Video conference unit is done on HQ-ASA.

The interface of HQ router that is facing to ISP is configured with subinterface and the L3Switch on both BR and HQ are 6500 series switch.

I have tried below config on HQ internet Router

access-list 120 permit tcp any any range 3230 3231

access-list 120 permit udp any any range 3230 3235

class-map match-all video-conf

match access-group 120

policy-map video-police

class video-conf

priority 6000

class class-default

fair-queue 128

interface <-sub-interface>

service-policy out video-police

As soon as I applied , the below error message was showing in router.

CBWFQ : Not supported on subinterfaces

Then i tried adding the same on BR-L3Swicth and below error message was showing.This might be because of IOS limitation.

priority command is not supported in output direction for this interface Configuration failed!

Could you please help me how to achive my requirement and where to apply the QOS with CLI commands config help.

Regards,

Jonathan Schulenberg · ‎05-05-2012

First we need to set an expectation: It's not possible to prioritize bandwidth inbound from the internet. The provider edge router at your Internet carrier would need to prioritize the video packets as they egress their router under the 32Mbps policer they have applied. This of course isn't an option. Prioritizing them at ingress on your HQ-Router is pointless since the access rate of the Ethernet interface cannot be overrun by 32Mbps worth of traffic. All you can do is prioritize the egress traffic toward the Internet.

Additionally you need to speak with your MPLS carrier on the 100Mbps link between the Branch and HQ. If it's MPLS you do not have a psuedo-wire or point-to-point link; congestion within the carrier could easily impact your video traffic. You need the carrier to also do differentiated service and offer an improved SLA for the 6Mbps worth of video traffic you want to pass through them.

To answer your subinterface question: The policy-map should be applied to the physical interface of the HQ-Router, not the subinterface. It will work apply all sub-interfaces since all of those sub-interfaces are sharing the same bandwidth (i.e. the Ethernet interface).

With regards to your inability to add the priority command on ingress: The 6500's support of MQC depends heavily on what line/feature cards you have installed. Here's the documentation on it; I suggest spending some time reading through this:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/configuration/guide/qos.html#wp1465326

s.aliyarukunju · ‎05-07-2012

Hi Jonathan,

Many thanks for your help.

So as per the advice i should apply the service policy in outbound direction of interface that is pointing to Internet Service Provider. And also i will apply it on parent interface instead of sub-interface.

Regards