As Wlan networks are becoming more and more popular in Enterprise networks I will list a few features that can be used to optimize network performance with regards to data rates, bandwidth and signal strength and coverage.
For this example let us consider the topology below:
In the setup above I used an AC6005-8 running system software version V200R005C00SPC200, 6 AP5030DN running software version V200R005C00SPC200 and a S5700-52C-PWR-EI that servers as a access switch and as POE source for the 6 APs.
The configuration of the AC is listed below:
#
vlan batch 251 to 252 254
#
wlan ac-global country-code GB
#
interface Vlanif1
ip address 192.168.254.15 255.255.255.0
#
interface Vlanif254
#
interface GigabitEthernet0/0/1
port hybrid pvid vlan 254
undo port hybrid vlan 1
port hybrid untagged vlan 254
#
interface GigabitEthernet0/0/2
port hybrid tagged vlan 251 to 252
#
interface GigabitEthernet0/0/3
#
interface GigabitEthernet0/0/4
#
interface GigabitEthernet0/0/5
#
interface GigabitEthernet0/0/6
#
interface GigabitEthernet0/0/7
#
interface GigabitEthernet0/0/8
#
interface Wlan-Ess1
#
interface NULL0
#
ip route-static 0.0.0.0 0.0.0.0 192.168.254.250
#
wlan
wlan ac source interface vlanif1
ap-region id 0
ap-region-name MainOffice
country-code GB
calibrate 2.4g 20mhz channel-set 1,2,3,4,5,6,7,8,9,10,11
ap-region id 1
ap-region-name Branch
country-code GB
ap id 0 type-id 35 mac AAAA-AAAA-AAAA sn 21000000000000000000
keep-service enable allow new-access
region-id 1
access priority normal
lineate-port gigabitethernet 0 vlan tagged 251
lineate-port gigabitethernet 0 vlan untagged 1
ap id 1 type-id 35 mac BBBB-BBBB-BBBB sn 21000000000000000000
keep-service enable allow new-access
access priority normal
lineate-port gigabitethernet 0 vlan tagged 251
lineate-port gigabitethernet 0 vlan untagged 1
ap id 2 type-id 35 mac CCCC-CCCC-CCCC sn 21000000000000000000
keep-service enable allow new-access
region-id 1
access priority normal
lineate-port gigabitethernet 0 vlan tagged 251
lineate-port gigabitethernet 0 vlan untagged 1
ap id 3 type-id 35 mac DDDD-DDDD-DDDD sn 21000000000000000000
keep-service enable allow new-access
access priority normal
lineate-port gigabitethernet 0 vlan tagged 251
lineate-port gigabitethernet 0 vlan untagged 1
ap id 4 type-id 35 mac EEEE-EEEE-EEEE sn 21000000000000000000
keep-service enable allow new-access
access priority normal
lineate-port gigabitethernet 0 vlan tagged 251
lineate-port gigabitethernet 0 vlan untagged 1
ap id 5 type-id 35 mac AAAA-BBBB-CCCC sn 21000000000000000000
keep-service enable allow new-access
access priority normal
wmm-profile name Wlan id 0
undo wmm enable
traffic-profile name Wlan id 0
security-profile name Wlan id 0
security-policy wpa2
wpa2 authentication-method psk pass-phrase cipher %@%@"4c]OAp|.OUugt9Ofvf(n.GD%@%@
encryption-method ccmp
service-set name Wlan id 0
max-user-number 128
wlan-ess 1
ssid Wlan
traffic-profile id 0
security-profile id 0
service-vlan 251
home-agent ac
calibrate enable auto interval 60
calibrate 2.4g 20mhz channel-set 1,2,3,4,5,6,7,8,9,10,11
radio-profile name Wlan id 0
wmm-profile id 0
undo calibrate enable
beamforming enable
ap 0 radio 0
radio-profile id 0
service-set id 0 wlan 1
ap 0 radio 1
radio-profile id 0
ap 1 radio 0
radio-profile id 0
channel 20MHz 11
service-set id 0 wlan 1
ap 1 radio 1
radio-profile id 0
ap 2 radio 0
radio-profile id 0
channel 20MHz 7
service-set id 0 wlan 1
ap 2 radio 1
radio-profile id 0
ap 3 radio 0
radio-profile id 0
channel 20MHz 5
service-set id 0 wlan 1
ap 3 radio 1
radio-profile id 0
ap 4 radio 0
radio-profile id 0
channel 20MHz 9
service-set id 0 wlan 1
ap 4 radio 1
radio-profile id 0
ap 5 radio 0
radio-profile id 0
service-set id 0 wlan 1
ap 5 radio 1
radio-profile id 0
#
After applying this configuration all
APs are registered and working as you can see in the output below:
<AC6005>display ap all
All AP information:
Normal[6],Fault[0],Commit-failed[0],Committing[0],Config[0],Download[0]
Config-failed[0],Standby[0],Type-not-match[0],Ver-mismatch[0]
------------------------------------------------------------------------------
AP AP AP Profile AP AP
/Region
ID Type MAC ID State Sysname
------------------------------------------------------------------------------
0 AP5030DN AAAA-AAAA-AAAA 0/1 normal ap-0
1 AP5030DN BBBB-BBBB-BBBB 0/0 normal ap-1
2 AP5030DN CCCC-CCCC-CCCC 0/1 normal ap-2
3 AP5030DN DDDD-DDDD-DDDD 0/0 normal ap-3
4 AP5030DN EEEE-EEEE-EEEE 0/0 normal ap-4
5 AP5030DN AAAA-BBBB-CCCC 0/0 normal ap-5
------------------------------------------------------------------------------
Problems begin to appear when users go online and start their daily activity that consists of backup data through the wireless network and accessing remote servers.
To determine the current network performance we performed a ping test and the result consisted of very long ping times and large jitter values:
To fix this we performed the following
steps:
1. undo the beamforming feature as this configuration is not recommended
in an office environment:
#
radio-profile name Logistik id 0
wmm-profile id 0
undo calibrate enable
undo beamforming enable
#
2. configure a short guard interval so
you can obtain higher data rates:
#
radio-profile name Logistik id 0
80211n guard-interval-mode short
80211ac guard-interval-mode short
#
3. Higher data rates can be obtained by modifying the channel bandwidth to 40MHz
#
ap 1 radio 0
radio-profile id 0
channel 40mhz-plus 11
service-set id 0 wlan 1
#
These changes brought the setup to a much better performance as ping times are now under 10ms. The only remaining issue is a packet interruption (about 8 to 10 packets are lost) that occurs each hour as you can see in the output below:
This failure is caused by device calibration that is configured at every 60 minutes. During device calibration the APs do not send or receive service packets, thus data loss can be observed.
To fix this issue a longer calibration
interval needs to be considered. The recommended interval for indoor Wlans is
720 minutes and we can configured as below:
#
calibrate enable auto interval 720
#
After the last change specified we obtained a optimal and reliable network with data rates at peak values.
