Wireless Access

After moving our AP's from older controllers running 5.4 code to new 7220's running 6.3.1.5 our cisco 7921 and 7925 phones are having a lot of trouble connecting. Many times thoughout the day the phone re-registeres with the call manager. Looking at the voice logs I see a lot of faild called. I searched the fourm and found someone had posted a VRD link for the 7921 the post was from 2012 and now the link isn't working. I called Aruba TAC support they didn't seem to know anything how to fix it. 

The Roaming VRD here:  http://www.arubanetworks.com/wp-content/uploads/DG_Roaming.pdf has a config stub for Cisco wireless phones.  Pay attention to the max and min ARM tx.  It is very important.  The only difference is that the portion under rf ht-radio-profile should be CSD override, instead of single chain legacy.

rf ht-radio-profile <802.11a ht radio profile>

   single-chain-legacy   CSD override

We also noticed 5 phones when you make a call the audio doesn't work but the phone conencts just no audio. 

Flawless phone quality requires very good RF and density that is greater than typical coverage.  That has to be done before anything can be troubleshot.  One way audio, silence, etc can all be traced back to RF issues, so the RF needs to be tuned appropriately.  Please take a look at the roaming VRD for ideas on what to do with your RF for voice.

Why woudl it work perfectly when the AP-70's and 65's were running on the old 800 controller using 3.3.3.3 but once we moved it to the new controllers we have issues. The configuration on both controllers are the same where they match up some new settins are not on the old controller, but we are  using all the default settings on the new controller. I will check into the VRD they talked about code versoins from a long time ago, but should still apply

Here is the settings on our controller

(DVDM-ARUBA-01) #show rf ht-radio-profile default-a

High-throughput radio profile "default-a" (Predefined (editable))
-----------------------------------------------------------------
Parameter Value
--------- -----
40 MHz intolerance Disabled
Honor 40 MHz intolerance Enabled
CSD override Disabled

(DVDM-ARUBA-01) #show rf ht-radio-profile default-g

High-throughput radio profile "default-g" (Predefined (editable))
-----------------------------------------------------------------
Parameter Value
--------- -----
40 MHz intolerance Disabled
Honor 40 MHz intolerance Enabled
CSD override Disabled

Adaptive Radio Management (ARM) profile "default"
-------------------------------------------------
Parameter Value
--------- -----
Assignment single-band
Allowed bands for 40MHz channels a-only
80MHz support Enabled
Client Aware Enabled
Max Tx EIRP 127 dBm
Min Tx EIRP 15 dBm
Rogue AP Aware Disabled
Scan Interval 10 sec
Aggressive scanning true
Active Scan Disabled
ARM Over the Air Updates Enabled
Scanning Enabled
Multi Band Scan Disabled
VoIP Aware Scan Enabled
Power Save Aware Scan Disabled
Video Aware Scan Enabled
Ideal Coverage Index 10
Acceptable Coverage Index 4
Free Channel Index 25
Backoff Time 240 sec
Error Rate Threshold 50 %
Error Rate Wait Time 30 sec
Channel Quality Aware Arm Disabled
Channel Quality Threshold 70 %
Channel Quality Wait Time 120 sec
Minimum Scan Time 8
Load aware Scan Threshold 1250000 Bps
Mode Aware Arm Disabled
Scan Mode all-reg-domain
Cellular handoff assist Disabled
Client Match Enabled
Client Match report interval (sec) 30
Allows Client Match to automatically clear unsteerable clients after ageout Enabled
Client Match Unsteerable Client Ageout Interval 2 Days 0 Hours
Client Match Band Steer A Band Min Signal (-dBm) 75
Client Match Sticky Client Check Interval (sec) 3
Client Match Sticky client check SNR (dB) 25
Client Match SNR threshold(dB) 10
Client Match Sticky Min Signal 70
Client Match Restriction timeout (sec) 10
Client Match Load Balancing threshold (%) 20
Client Match VBR Stale Entry Age (sec) 120
Client Match Max steer failures 3
Client Match Load Balancing client threshold 10
Client Match Load Balancing SNR threshold (dB) 30
Client Match Load Balancing signal delta bound (dB) 5

Max Tx EIRP 127 dBm
Min Tx EIRP 15 dBm

It should be 18 max and 12 min, just like the VRD says for the Cisco configuration.  There are also parameters that you need to manipulate for the SSID profile that the phone connects to.  The physics of a non-802.11n and an 802.11n WLAN are different, not to mention that the patterns, and diversity differences between the access points.  Those differences loom large for a delay, latency and loss sensitive application like voip.

Thanks for the information too bad TAC support didn't know any of this when I called in about it a month ago. Frankly I'm suprised beacuse normally Aruba TAC is very good. Maybe the person I was dealing with had little experince with wireless phones. The strange thing is a past co worker who now is in the middle of a large cisco phone upgrade at another company said they are pulling out all cisco wireless phones and replacing with cordless base stations because of all the issues they have had. The funny part is they are using Cisco for the wireless system.  

Ill go though the docement and put together the changes at last site we rolled the AP's over to the new controller.Be a good test I can create new profiles for that AP group. 

Checking into out ssid profile everything is set accroding to the document by default except DTIM period which I will change tonight.  I'm not sure on the RF profile changes because that will effect all devices connected not just phones.  These 2 changes

max power settings to 18 and min 12 ours is set to min 15 and max 127

rf arm-profile "802.11a arm profile name>"
max-tx-power 18
min-tx-power 12
voip-aware-scan
!
rf ht-radio-profile <802.11a ht radio profile>
single-chain-legacy

SSID enable Enabled
ESSID VOIP-NET
Encryption wpa-psk-tkip
DTIM Interval 1 beacon periods
802.11a Basic Rates 6 12 24
802.11a Transmit Rates 6 9 12 18 24 36 48 54
802.11g Basic Rates 1 2
802.11g Transmit Rates 1 2 5 6 9 11 12 18 24 36 48 54
Station Ageout Time 1000 sec
Max Transmit Attempts 8
RTS Threshold 2333 bytes
Short Preamble Enabled
Max Associations 64
Wireless Multimedia (WMM) Enabled
Wireless Multimedia U-APSD (WMM-UAPSD) Powersave Enabled
WMM TSPEC Min Inactivity Interval 0 msec
Override DSCP mappings for WMM clients Disabled
DSCP mapping for WMM voice AC N/A
DSCP mapping for WMM video AC N/A
DSCP mapping for WMM best-effort AC N/A
DSCP mapping for WMM background AC N/A
Multiple Tx Replay Counters Disabled
Hide SSID Disabled
Deny_Broadcast Probes Disabled
Local Probe Request Threshold (dB) 0
Disable Probe Retry Enabled
Battery Boost Disabled
WEP Key 1 N/A
WEP Key 2 N/A
WEP Key 3 N/A
WEP Key 4 N/A
WEP Transmit Key Index 1
WPA Hexkey N/A
WPA Passphrase 
Maximum Transmit Failures 0
EDCA Parameters Station profile N/A
EDCA Parameters AP profile N/A
BC/MC Rate Optimization Disabled
Rate Optimization for delivering EAPOL frames Enabled
Strict Spectralink Voice Protocol (SVP) Disabled
High-throughput SSID Profile default
802.11g Beacon Rate default
802.11a Beacon Rate default
Advertise QBSS Load IE Disabled
Advertise Location Info Disabled
Advertise AP Name Disabled
802.11r Profile N/A
Enforce user vlan for open stations Disabled