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Priority Queuing & Qos

Level 1
Level 1

Merry Christmas !


We have a 2MB point to point link with the ISP for Internet access for our Company users and BW usage always hits maximum. We are going to introduce the Video conferencing system which we will use same 2 MB line , will have Video conferencing with International customers weekly 3 times and conferencing will last for 1 hour.My request is , during the Video conferencing time, I want to prioritize the H.323 protocol than HTTP protocol on same 2MB line. During normal time, all 2MB should be used for HTTP traffic. In current scenario, I'm stopping the Internet access completely (disable the Proxy service ) during the Video conferencing time. Pls note that this 2MB is configured on Fast ethernet Internet interface on a Router which is connected with Radio link modem (Ericsson device ).

Thanks in advance.


8 Replies 8

Hello Raju,

is there any other video conferencing going on besides those times when you want to prioritize the H323 traffic ? If so, you could use LLQ n combination with a time-based access list, the configuration would look like this:

ip access-list extended H323

permit tcp any any eq 1720 time-range CONFERENCE


time-range CONFERENCE

periodic Tuesday 14:00 to 15:00

periodic Thursday 15:00 to 16:00

periodic Friday 13:00 to 14:00


class-map match-all VIDEO

match access-group name H323



class VIDEO

priority 2000


interface FastEthernet0/0

service-policy output VIDEO_CONFERENCE

If you just have the video conferencing going on 3 times a week, you do not need the time-based access-list. Whenever there is congestion and H323 traffic, the traffic will get the full 2MB bandwidth.

Just be careful that the H323 traffic does not completely saturate the link and causes problems with any routing or other control traffic. You might want to specify only 1.75MB...