AI Roaming Does Not Take Effect
Symptom
AI roaming does not take effect for STAs.
Possible Causes
- Independent radio scanning is disabled.
- Terminal type identification is disabled.
- AI roaming is disabled.
- No Layer 2 link is available between the associated AP and neighboring AP.
- The associated AP and neighboring AP are not configured with the same SSID and same authentication mode.
- The air scan function is disabled on the target AP.
- The STA does not support the working channel of the neighboring AP.
- The STA does not support LM or TPC measurement.
- The AC does not deliver the STA profile, or the capabilities are not supported in the STA profile.
- The RSSI difference between the associated AP and neighboring AP at the location of the STA does not reach the threshold for triggering roaming.
Troubleshooting Procedure
- Check whether APs are working in independent radio scanning mode.
AI roaming steering based on coordinated measurement requires that APs use the independent scanning radio to scan the air interface environment. Therefore, the APs must work in independent radio scanning mode.
On the AC, check whether the APs work in independent radio scanning mode.
<AC> display ap radio-mode all -------------------------------------------- ID Mode -------------------------------------------- 4 2radio-independent-scan 8 2radio-independent-scan --------------------------------------------
If an AP does not work in independent radio scanning mode (2radio-independent-scan), you can enable independent radio scanning for the AP system profile to which the AP belongs.
<AC> system-view [AC] wlan [AC-wlan-view] ap-system-profile name default [AC-wlan-ap-system-prof-default] radio-mode 2radio-independent-scan Warning: Modifying the radio mode may reset the AP. Continue?[Y/N]y
The 2radio-independent-scan mode takes effect only on APs that support independent radio scanning. Run the display ap-type command on the AC to check the radio mode supported by the AP (based on the Radio mode field in the command output).
Independent radio scanning is available for the AirEngine 6760-X1, AirEngine 6760-X1E, and AirEngine 5760-51 only with the RTU license loaded. Run the display ap-rtu-status all command on the AC to check the loading status of the RTU license on an AP (based on the RTU status field in the command output). If no RTU license is loaded, install an RTU license by referring to the License Usage Guide.
- Check whether the terminal type identification function is enabled.
Personalized roaming steering based on STA profiles depends on the terminal type identification function.
Check whether the terminal type identification function is enabled in the AP system profile to which the AP belongs.
<AC> display ap-system-profile name default ... Terminal identify : enable ...
The terminal type identification function is enabled by default. If this function is disabled, enable it.
<AC> system-view [AC] wlan [AC-wlan-view] ap-system-profile name default [AC-wlan-ap-system-prof-default] undo terminal-identify disable
- Check whether the AI roaming function is enabled.
<AC> display rrm-profile name default ... Smart-roam : enable Smart-roam AI mode : enable ...
The AI roaming function is enabled by default. If this function is disabled, enable it.
<AC> system-view [AC] wlan [AC-wlan-view] rrm-profile name default [AC-wlan-rrm-prof-default] smart-roam ai-mode
The AI roaming function it takes effect only for new STAs who go online after the function is enabled. For an online STA before the AI roaming function is enabled, this function takes effect only after the STA roams or reassociates and goes online.
- Check whether a Layer 2 link is set up between the associated AP and the target AP.
AI roaming works on Layer 2 between APs and therefore depends on the Layer 2 link between the associated AP and the target AP.
On the AP, you can view information about neighboring APs that have established links with it (based on the Link state field in the command output).
[AP-diagnose] display wsrv neighbor-ap all ------------------------------------------------------------------------------- Type : band-navi MAC : 00e0-fc9d-e760 IP : 192.168.100.162 Link ID : 18 Link state : Connected Expire time : 9D:23H:59M:40S Send msg total : 11163 Receive msg total : 11175 -------------------------------------------------------------------------------
Link state:
- IDLE: This is the initial state.
- Connecting: A link is being set up.
- Connected: A link has been set up.
Correctly configure the basic WLAN networking and wait until the link is set up successfully after the AP goes online. If the link cannot be established for a long time, for example, the neighboring AP cannot be pinged, the Layer 2 network between the associated AP and the target AP is disconnected. Check whether port isolation is configured on the network to resolve the Layer 2 networking problem.
- Check whether the VAP configuration on the AP is proper.
Check whether the same SSID and authentication policy are configured for the VAPs on the same frequency band of the associated AP and the target AP.
<AC> display vap all Info: This operation may take a few seconds, please wait. WID : WLAN ID ----------------------------------------------------------------------------------------------- AP ID AP name RfID WID BSSID Status Auth type STA SSID ----------------------------------------------------------------------------------------------- 4 AP-4 1 1 00e0-fc9D-E760 ON Open 0 5g 8 AP-8 1 1 00e0-fc44-0010 ON Open 0 5g -----------------------------------------------------------------------------------------------
If the VAP configuration of the associated AP is different from that of the target AP, modify the configuration.
Currently, AI roaming can be implemented only for STAs working on the 5 GHz frequency band.
- Check whether the air scan function is enabled on the AP.
AI roaming depends on the air interface scanning function of the AP. Ensure that this function is enabled.
<AC> display air-scan-profile name default -------------------------------------------------------------------- Scan switch : enable Scan period(ms) : 80 Scan interval(ms) : 3000 Scan channel-set : dca-channel Voice scan aware : enable Video scan aware : enable Scan enhancement : disable --------------------------------------------------------------------
The air scan function is enabled by default. If this function is disabled (Scan switch: disable), enable it.<AC> system-view [AC] wlan [AC-wlan-view] air-scan-profile name default [AC-wlan-air-scan-prof-default] undo scan-disable
- Check whether the STA supports the working channel of the target AP.
Check the working channel of the target AP on the AC.
<AC> display radio all Info: This operation may take a few seconds. Please wait for a moment.done. CH/BW:Channel/Bandwidth CE:Current EIRP (dBm) ME:Max EIRP (dBm) CU:Channel utilization ST:Status WM:Working mode (normal/monitor/monitor dual-band-scan/monitor proxy dual-band-scan) -------------------------------------------------------------------------------------------------------- AP ID Name RfID Band Type ST CH/BW CE/ME STA CU WM -------------------------------------------------------------------------------------------------------- 4 AP-4 0 2.4G 11ax on 1/20M 29/29 0 72% normal 4 AP-4 1 5G 11ax on 157/20M 31/31 0 9% normal 8 AP-8 0 2.4G 11ax on 2/20M 9/34 0 32% normal 8 AP-8 1 5G 11ax on 149/20M 15/38 1 3% normal --------------------------------------------------------------------------------------------------------
Check the channel set supported by the STA on the AC. If the STA does not support the working channel of the target AP, AI roaming cannot be performed.
<AC> display station sta-mac 00e0-fc89-2428 -------------------------------------------------------------------- ... Supported 5G channels : 36,40,44,48,52,56,60,64 : 149,153,157,161,165 ... -------------------------------------------------------------------- - Check whether the STA supports LM/TPC measurement.
AI roaming steering based on coordinated measurement uses the LM or TPC measurement mechanism to obtain the RSSIs of STAs. If a STA does not support LM or TPC measurement, AI roaming cannot be performed.
Check the LM/TPC capability of the STA on the AC.
<AC> display station sta-mac 00e0-fc89-2428 -------------------------------------------------------------------- ... Link measurement : Yes Transmit power adaptation : Yes ... --------------------------------------------------------------------
- Check whether the STA matches a correct STA profile.
In the AI roaming mechanism, the AC delivers the STA profile library to APs, which match STAs against STA profiles and perform personalized roaming steering.
If the AC does not deliver the corresponding STA profile or the STA profile does not match, the possible causes are as follows:
- The terminal type identification function is not enabled. (Check and enable this function by referring to Step 2.)
- The STA is in sleep state or does not generate network packets. As a result, APs cannot identify the terminal type (the terminal attempts to use the network app to exchange network packets).
- The STA model does not match the existing profile.
Check STA profile information matched by the STA on the AC. (Check the state field in the command output. The value of unmatched indicates that no STA profile is matched.)
[AC-diagnose] display wlan wsta profile sta-mac 00e0-fc89-2428 ---------------------------------------------------- staMac : 00e0-fc89-2428 state : unmatched ... ----------------------------------------------------
Check profile information about all STAs on the AC.
<AC> display sta-profiling ------------------------------------------------------------------------------ Type Type ID OS OS ID Priority ------------------------------------------------------------------------------ ... Mate 40 Pro 32454 Android 10 17765 1188 Mate 40 32455 Android 17763 1189 ... ------------------------------------------------------------------------------
- STA profiles on the AC are not delivered to the AP.
If the network communication between the AC and AP is abnormal, for example, packet loss occurs, the AP may fail to receive the delivered profile configuration.
Check STA profile information on the AP.
[AP-diagnose] display umac ai-roam sta-portrait all ------------------------------------------------------------------------ Index MAC TypeID OsID Update time ------------------------------------------------------------------------ 0 00e0-fc89-2428 12791 17763 2021-07-29 21:32:05 ------------------------------------------------------------------------ Total : 1
Check detailed information about the matched STA profile on the AP.
[AP-diagnose] display umac ai-roam sta-portrait mac 00e0-fc89-2428 ------------------------------------------------------------------- MAC : 00e0-fc89-2428 TypeID : 12791 OsID : 17763 Priority : 175 Update time : 2021-07-29 21:32:05 Link measurement ability : yes TPC ability : no 802.11v ability : no 802.11v assoc value : -10 802.11v target value : -10 802.11v different value : 100 Steer wait time (s) : 4 Prefer cand list : 1 Abridged flag : 1 Validity interval (TBTTs) : 50 Disassoc imminent : 1 Disassoc timer (TBTTs) : 0 BSS termination : 0 Ess disassoc imminent : 0 -------------------------------------------------------------------
Check the LM/TPC capability of the STA on the AP.
[AP-diagnose] display umac station mac 00e0-fc89-2428 -------------------------------------------------------------------- ... Link measurement : Yes Transmit power adaptation : Yes ... --------------------------------------------------------------------
Check whether the LM and TPC capabilities of the STA are consistent with those in the profile. The AI roaming mechanism performs coordinated measurement on the STA only when the required capabilities are supported by both the STA and the STA profile.
Check whether the value of 802.11v ability in the matched STA profile is yes. Only 802.11v-capable STAs support AI roaming.
The LM and TPC capabilities displayed by running the display umac station mac xxxx-xxxx-xxxx command on the AP are the same as those displayed by running the display station sta-mac xxxx-xxxx-xxxx command on the AC. Both of them are the capability values carried in the Assoc packet of the STA, indicating that the STA claims to support the corresponding capabilities. Packets are exchanged only when the STA claims to support the LM or TPC capability. If the LM and TPC capabilities queried on the AC and AP are different, the network connectivity may be abnormal. Check the network between the AC and AP.
Run the display umac ai-roam sta-portrait mac xxxx-xxxx-xxxx command on the AP to check the LM, TPC, and 802.11v capabilities of the STA. The capabilities may be different from the actual capabilities of the STA, which is normal. Only one of the supported capabilities is displayed in the profile because a single STA uses only one of the capabilities for measurement to determine whether roaming is required.
- Check whether the STA meets roaming conditions.
- To prevent frequent roaming, coordinated measurement is performed only when the RSSI of the associated AP is less than the downlink RSSI threshold (–60 dBm). In addition, the downlink RSSI threshold is reduced each time the coordinated measurement of AI roaming is triggered, thereby suppressing roaming.
Check the downlink RSSI threshold for coordinated measurement on the AP.
[AP-diagnose] display umac ai-roam neighbor-measure-list mac 00e0-fc89-2428 ------------------------------------------------------------------------------------------------------------ The first line is the information about the AP associated with the station. ------------------------------------------------------------------------------------------------------------ Downlink rssi threshold : -60 Measurement mode : LM ------------------------------------------------------------------------------------------------------------ Index Ap MAC Uplink rssi Downlink rssi Link margin Transmit power Frequency band Refresh time ------------------------------------------------------------------------------------------------------------ 0 00e0-fc16-7980 -58 -64 14 40 5G 0S 1 00e0-fc16-7981 -48 -34 44 40 5G 0S ------------------------------------------------------------------------------------------------------------ Total : 2
The preceding example shows the measurement result of the STA. The first row indicates the measurement data of the associated AP. When the downlink RSSI of the associated AP is lower than the threshold, coordinated measurement is triggered, and the STA measures the RSSI of the neighboring AP.
- By default, AI roaming is triggered only when the downlink RSSI of a neighboring AP measured on the STA is at least 15 dB higher than that of the associated AP. This prevents the STA from roaming frequently between two neighboring APs. After the SNR margin roaming thresholds are configured, the STA selects a neighboring AP for AI roaming. You can set the SNR margin roaming thresholds to adjust the sensitivity for triggering roaming steering.
Check the SNR margin roaming thresholds that trigger STA roaming steering on the AC.
<AC> display rrm-profile name default -------------------------------------------------------------------- ... Smart-roam high level SNR margin(dB) : 15 ... --------------------------------------------------------------------
Modify the SNR margin roaming thresholds on the AC. (In AI roaming based on coordinated measurement, high-level-margin is used to determine whether to steer STAs to roam to neighboring APs.)
<AC> system-view [AC] wlan [AC-wlan-view] rrm-profile name default [AC-wlan-rrm-prof-default] smart-roam snr-margin high-level-margin 10 low-level-margin 6
- Check AI roaming records of the STA.
<AC> display station steer-history S/T/A:Source/Target/Actual Flag:P[AI Profiling STA] V[Voice/Video/Active STA] BTM success times/BTM total times:12828/23429 Deauth success times/Deauth total times:0/0 ------------------------------------------------------------------------------------------------------------------------------------ Time Sta Device(S/T/A) Radio(S/T/A) Rssi(S/T/A) Reason Move-mode BTM_CODE Flag Result ------------------------------------------------------------------------------------------------------------------------------------ 2021-01-01/00:00:00 00e0-fc89-2428 1000/2000/2000 1/1/1 -60/-50/-50 AI BTM 0 P Success .... ------------------------------------------------------------------------------------------------------------------------------------
- To prevent frequent roaming, coordinated measurement is performed only when the RSSI of the associated AP is less than the downlink RSSI threshold (–60 dBm). In addition, the downlink RSSI threshold is reduced each time the coordinated measurement of AI roaming is triggered, thereby suppressing roaming.
