802.11e marking of signalling-traffic

[heinz.kern]

hello,

we have several 7921 voip-over-wireless phones and see this problem: the phone uses dscp 24 (CS3) for signalling traffic. nevertheless when this frame arrives at the access-point and is tunneled through capwap the dscp-value of the capwap-packet is 26 (AF31). the reason for that is that the access-point looks on the 802.11e-tag of the wireless-frame (which is 4). and this is mapped to 26.

as i found out up to now: AF31 is the old standard and the ip-phone already uses the new one (CS3). but the access-points converts it still to old one -->AF31 (based on the 802.11e-tag of 4).

is there a possibility to change the behaviour on the access-point so that a common policy is possible??

thanks

heinz

[Federico Lovison · Accepted solution]

Hi Heinz,

You're right, the AP uses the 802.11e marking to derive the DSCP marking for the LWAPP/CAPWAP packet.

You can find more info on how the DSCP <-> 802.11e mapping happens on the WLC:

http://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch5_QoS.html#wp1051421

As you can see, the 802.11e value of 4 is translated to DSCP 26 (AF31)

This table cannot be changed on the AP/WLC.

I hope this helps.

Regards,

Federico

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