DSCP AF12

[marta_garrido]

Hi all,

From some days ago we are seeing a problem of jitter increased jitter in some telepresence sessions that go through a multipoint switch. We reviewed the network and there aren't problems.

What we have found is that in some multipoint sessions, not all the rooms are negotiating with the QoS traffic marking DSCP AF41, but some rooms remain in AF12 during the call and just those rooms (in AF12) the people on the meeting are complaining of poor quality in the video, picture freeze, video cuts.

Can be the problem with the multipoint switch that not all rooms to negotiate AF41? Is it possible to increase the jitter for this reason?

[Johan Vermaelen]

Hi Marta,

Where do you see the AF12 listed? If that is in the CTS logs, those values relate to the audio/video streams that the room is receiving from the multipoint switch, and the QoS marking configuration on the MCU is a global setting (configure -> system setting -> QoS if you are using a CTMS).

Check the MCU to make sure the config on there is set correctly to mark your CTS media as AF41. If that is the case then the most likely reason for some rooms receiving the traffic marked AF12, while all others are receiving AF41, is that the traffic to some of the rooms is getting remarked on the path between the MCU and the room, in which case you need to work with the network admins to find out where and why this remarking takes place.

Hope this helps,

Johan