video phone with Qos

[ahmadabuzayyad]

what is the configuration to prioritize the traffic for video phone when connecting two branch through WAN?

I read that for wan, we use ToS, what that mean? and how we can configre router 3800 series for that option?

[Brandon Buffin]

The QoS configuration will depend on the type of unity that you are using. The following link gives an example for Polycom Video units.

http://www.cisco.com/en/US/tech/tk1077/technologies_configuration_example09186a0080111c1b.shtml

If the device marks packets with a DSCP value, you could also match on that. Matching on DSCP would change the class map to:

class-map match-all video

match ip dcsp af41

Hope this helps. If so, please rate the post.

[ahmadabuzayyad]

the link was helpful, but i have more question if you can help me ?

the vedio phone from huawie and let me use dcsp from 0 to 63 but it doesn't include af41 and what that mean, the second thing if i have link speed 1 Mbps what is the prefer prioirity give for video?

thanks

[Brandon Buffin]

AF41 is actually a Per Hop Behavior (PHB) which basically tells a DiffServ compliant node how to treat a packet. The decimal DSCP value for AF41 is 34. AF41 is the recommended PHB for video. Take a look at the following link for more information on PHBs. The bandwidth you reserve for video will depend on the data rate supported by your video unit. The link below gives details on capacity planning for video. You'll need to consider the data rate for your video unit, how many video units you have, and how many should be able to make simultaneous calls across the WAN. As referenced in the link, if your video units are capable of consuming more bandwidth than you have available, you will need to implement some for of Call Admission Control (CAC).

http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a0080087afb.html

http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_note09186a0080094968.shtml#cap_plan

Hope this helps. If so, please rate the post.

Brandon

[ahmadabuzayyad]

thanks alot for this information.

and I need more two questions?

first, can I connect three vedio phones to make one conferance if yes how ?

second, I saw in the configuration that gave me in the link contain:

-- Video-Conf Traffic

access-list 102 permit ip any any dscp cs4

access-list 102 permit ip any any dscp af41

!

! -- Streaming Traffic

access-list 103 permit ip any any dscp cs1

access-list 103 permit ip any any dscp af13

where he apply the value (cs4 and af41)?

on the vedio phone or what ?

the same things for cs1 and af13 ?

[Brandon Buffin]

The ability to connect 3 video endpoints will be dependent on your hardware. In general, the answer is yes, this is possible. Take a look at the manufacturer's website for the specific setup.

In this example, it is assumed that the video endpoint will mark the packets with the correct dscp, therefore making it possible to match the packets based on this marking. If the endpoint does not mark the correct dscp, you would need to match the video stream and control traffic based on another criteria such as port number.

Hope this helps. If so, please rate the post.

Brandon