Hi All,
Please bear with my numerous questions, but I'm sitting the lab very
soon hence lots of unanswered queries in my head. I was fiddling with
an auton 1242 and testing out various qos scenario and came across
this problematic configuration line: dot11 priority-map avvid.
I know this does what the WLC does in mapping 802.11e UP value of 6 to
802.1p COS 5 automatically. But on top of that it does many other
things unexplained in any doc.
When enabled, with qos mode wmm enabled by default without any cac
applied, any packets incoming from a 7921 automatically gets the
outbound cos tagged as 5 (as seen on switch mls qos statistics). No
policy map placed in any interface, in any direction (example
purposefully using policy-map letting class default traffic set cos to
4) can affect the outbound (towards LAN) cos value of 5. I presume the
7921 has a default outbound UP of 6 only recognised by the dot11
priority avvid command. However, without the avvid command and without
any policy-map to set any cos to the voice packets, the voice packets
default to COS0 and DSCP EF. Without the avvid command, the policy map
kicks in and works fine. Also as long as the avvid command is in
place, the policy-map doesn't match any packets from radio inbound and
Fa outbound. Only the Fa inbound and radio outbound hits the
policy-map counter.
I have also tested with IP Communicator to verify if the policy-maps
actually works when the avvid command is in place. Nope, the outbound
policy-map, be on the Fa or radio interface, do not get any hits.
However, the voice packets from the Ip Communicator is marked with
DSCP EF and UP 5. Hence, the AP converts the UP 5 to COS4 which is
shown in the switch qos statistics. When i shut down the IP
Communicator, my data packets are seen to be using DSCP 0 and COS0 on
the switch which shows that the IP Comm does mark dscp. However for
the UP value of IP Comms, without the avvid command, COS becomes 0 on
the switch statistics (DSCP still EF).
My conclusion: If this phenomenon is true, then with "dot11
priority-map avvid configured", no policy-map will work for any
LAN-bound traffic. The dot11 priority-map works well with the IP
Phones or devices with UP values (7921 in this case which sends UP 6
in the voice packets and IP comm send UP 5). However, without the
avvid command, policy-maps WILL work in both radio and fa interface
for LAN bound traffic but at the same time wireless client devices
with UP values will have their packets tagged as COS 0.
Any comments to disagree IS GREATLY APPRECIATED, but please include
the reasonings.
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