Symbol MC9090 Scan Guns- 2602i AP's/5508

Question

We have used the Symbol Scan guns for quite some time on our wireless networks.  Recently we upgraded a location that had Cisco 1242 AP's, to the newer 2602i model.  The controller is a 5508 on version 7.3, and the access points are operating in FlexConnect mode. 
Since upgrading to the 2602i AP's. we have had many issues with the Symbol MC9090 scan guns.  They appear to be roaming very frequently between AP's servicing this area.  At first we thought it was coverage, and added more access points.  We are still seeing the same problems.  The signal strength fluctuates on the scan gun from excellent to poor very often, and I notice packets getting dropped during this process.
The application runnig on the scan gun will halt, and either normailze or cause the device to have to be completely reset.  These problems were not happenng before we upgraded to the new model of AP.  I have read the document Cisco published concerning best practices for Symbol/Motorola scanners and controller based networks, but that is fairly old and out of date.  We do have CCKM, Aironet IE, and Band Select enabled on this WLAN.  I assume I should probably disable these features but we have other scan guns using this same WLAN with no problems.  The biggest change was when we went from the 1242 to the 2602i.  During this change, we also moved also from a controller where the AP's were in local mode, to now the access points operating in Flex connecting to a central controller.  Latency between the AP's and the controller is not a problem.
Any help would be greatly appreciated.

Answer 1

Hi Guys.
I was searching this forum for somone that is experiencing similar problems as we have currently.
We are using Autonomous 2602e with standard "rubber duck" antennas (AIR-ANT2524DB-R=) and Motorola MC17 and MK4900 wireless units. The clients (even stationary) are roaming excessively and have poor performance in wireless connectivity. RF is good(SNR and signal levels)
We have tried tuning the powerlevels to match the client. Other sites with (almost)identical configuration and environment (switches, vlans, firmware, etc) but with 1242AGN work excellent!
Client is roaming excessively without any apparent reason. When comparing 1242, the 2602 has spectrum intelligence and other RF enhancing function, but these are not activated. We have disabled 802.11n and speeds below 5.5Mbs(basic) the rest supported.
********* Config ***********
Current configuration : 5451 bytes
version 15.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime localtime
service password-encryption
hostname XXXXXXX
logging rate-limit console 9
aaa new-model
aaa group server radius rad_eap
server X.X.X.X
aaa group server radius rad_mac
server X.X.X.X
aaa group server radius rad_acct
server X.X.X.X
aaa group server radius rad_adm
server X.X.X.X
aaa authentication login eap_methods group rad_eap
aaa authentication login mac_methods group rad_mac
aaa authentication login admin group rad_adm local
aaa authentication enable default group rad_adm enable
aaa accounting exec default stop-only group rad_acct
aaa accounting network acct_methods stop-only group rad_acct
aaa session-id common
clock timezone +0100 1 0
no ip routing
ip domain name net.axfood.se
ip name-server X.X.X.X
dot11 syslog
dot11 vlan-name equipment vlan 60
dot11 vlan-name selfscanning vlan 40
dot11 vlan-name voice vlan 20
dot11 vlan-name default vlan 1
dot11 ssid EQUIPMENT
   vlan 60
   authentication open
   authentication key-management wpa
   wpa-psk ascii 7 X.X.X.X
dot11 ssid SCANNING
   vlan 40
   authentication open
   authentication key-management wpa version 1
   wpa-psk ascii 7 X.X.X.X
dot11 wpa handshake timeout 2000
dot11 network-map
power inline negotiation prestandard source
crypto pki token default removal timeout 0
username @@@@@@ privilege 15 password 7 XXXXX
bridge irb
interface Dot11Radio0
no ip address
no ip route-cache
encryption vlan 40 mode ciphers tkip
encryption vlan 60 mode ciphers tkip
ssid EQUIPMENT
ssid SCANNING
antenna gain 0     <--- I know this is wrong; should be 2 (AIR-ANT2524DW-R=)
stbc
speed  basic-5.5 11.0 6.0 9.0 12.0 18.0 24.0 36.0 48.0 54.0
power local 11
power client local
packet retries 128 drop-packet
channel least-congested 2412 2437 2462
station-role root
rts retries 128
no dot11 extension aironet
no cdp enable
interface Dot11Radio0.1
encapsulation dot1Q 1 native
no ip route-cache
bridge-group 1
bridge-group 1 subscriber-loop-control
bridge-group 1 spanning-disabled
bridge-group 1 block-unknown-source
no bridge-group 1 source-learning
no bridge-group 1 unicast-flooding
interface Dot11Radio0.20
encapsulation dot1Q 20
no ip route-cache
bridge-group 20
bridge-group 20 subscriber-loop-control
bridge-group 20 spanning-disabled
bridge-group 20 block-unknown-source
no bridge-group 20 source-learning
no bridge-group 20 unicast-flooding
interface Dot11Radio0.40
encapsulation dot1Q 40
no ip route-cache
bridge-group 40
bridge-group 40 subscriber-loop-control
bridge-group 40 spanning-disabled
bridge-group 40 block-unknown-source
no bridge-group 40 source-learning
no bridge-group 40 unicast-flooding
interface Dot11Radio0.60
encapsulation dot1Q 60
no ip route-cache
bridge-group 60
bridge-group 60 subscriber-loop-control
bridge-group 60 spanning-disabled
bridge-group 60 block-unknown-source
no bridge-group 60 source-learning
no bridge-group 60 unicast-flooding
interface Dot11Radio1
no ip address
no ip route-cache
shutdown
antenna gain 0     <--- I know this is wrong; should be 4 (AIR-ANT2524DW-R=)
no dfs band block
channel dfs
station-role root
no cdp enable
bridge-group 1
bridge-group 1 subscriber-loop-control
bridge-group 1 spanning-disabled
bridge-group 1 block-unknown-source
no bridge-group 1 source-learning
no bridge-group 1 unicast-flooding
interface GigabitEthernet0
no ip address
no ip route-cache
duplex auto
speed auto
interface GigabitEthernet0.1
encapsulation dot1Q 1 native
no ip route-cache
bridge-group 1
bridge-group 1 spanning-disabled
no bridge-group 1 source-learning
interface GigabitEthernet0.40
encapsulation dot1Q 40
no ip route-cache
bridge-group 40
bridge-group 40 spanning-disabled
no bridge-group 40 source-learning
interface GigabitEthernet0.60
encapsulation dot1Q 60
no ip route-cache
bridge-group 60
bridge-group 60 spanning-disabled
no bridge-group 60 source-learning
interface BVI1
ip address X.X.X.X 255.255.255.0
no ip route-cache
ip default-gateway X.X.X.X
ip http server
ip http authentication aaa
no ip http secure-server
ip http help-path
http://www.cisco.com/warp/public/779/smbiz/prodconfig/help/eag
ip radius source-interface BVI1
logging X.X.X.X
access-list 111 permit tcp any any neq telnet
snmp-server community XXxxxXX RW
radius-server attribute 32 include-in-access-req format %h
radius-server dead-criteria time 10 tries 3
radius-server host X.X.X.X key 7 DDDDdddddDDDDD
radius-server host X.X.X.X key 7 bbbbBBBBBbbbbb
radius-server retransmit 2
radius-server timeout 4
radius-server deadtime 1
radius-server vsa send accounting
bridge 1 route ip
line con 0
access-class 111 in
password 7 ppppppppPPPPppppppp
logging synchronous
login authentication admin
history size 50
line vty 0 4
access-class 111 in
logging synchronous
login authentication admin
history size 50
transport input ssh
line vty 5 15
exec-timeout 3 0
password 7 ppppppppPPPPppppppp
login authentication admin
history size 50
transport input ssh
sntp server X.X.X.X
sntp broadcast client
end
Is there any "hidden" rate, access limiting or load-balancing features on the 2602 access points?
This is causing major disruptions on the stores where the 2602e access points have been deployed.
Checking the the client statistics for signal and SNR gives no reason why stationary clients should roam unless the access points fails to acknowledge reassociation requests from the client.
One important information is that many simultaneous association requests for some access points due to the fact that many motorola devices(50-200) are aggregated in racks.
Sincere Regards
Any ideas?