Roaming Assist Guide

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Good Morning!

I'm implementing measures to improve WiFi in high density and critical environments. I have a scenario with 17,000 people passing by continuously.

Motorola left a very interesting role called Roaming Assist, but I did not find any deploy guides.

We have 6 functions to customize. I need help refining this functionality.

I would like tips used to keep clients connected to critical mission SSIDs and SSIDs for non-critical systems (avoid sticky clients)

Do you have any guides? The most I found was a motorola white paper explaining how the technology works.

Thanks!
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Richard Augusto

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Posted 5 months ago

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Andrew Blomley, Employee

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Roaming Assist works by monitoring the received rssi of the mobile device 

The access point monitors any device that the received rssi goes below detection-threshold.

When the device hits the handoff-threshold, the action is performed, in this case, assisted-roam

 

Below is an example policy

 

roaming-assist-policy <demo>

 aggressiveness lowest

 sampling-interval 15

 monitoring-interval 5

 handoff-count 3

 detection-threshold -65

 handoff-threshold -70

 action assisted-roam

 disassoc-time 5.

 

To assign this policy to a wlan.

 

select the wlan

Config

Wlan <wlan1>

Use roaming-assist-policy <demo>
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Richard Augusto

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Andrew,

Many thanks for the tips!

Folks,

I applied "Roaming Assist" and the performance of my network has improved a lot. I have a "Guest SSID" and this network is shared in an AP that has mission critical services. It is an interesting challenge to keep this infrastructure running in dense, high-flow environments.

The flow of people in this retail store where I work is very high, so keeping the solution optimized and with high availability is essential.

Chapter 30 (CLI GUIDE) was used as a guide in applying this feature.

It would be interesting for Extreme Networks to provide some examples for Roaming Assist to function properly in critical and non-critical environments and thus optimize the use of the WiNG solution. It follows as a suggestion, put in the manual of best practices.

Thank you!


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Andrew Blomley, Employee

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---------

To me this is a very interesting topic. How devices join and roam on a network is key to its successful operation. I am a big fan of Smart-RF but Smart-RF does not replace good RF-design. Smart RF takes a good design and optimises it for the here and now.

 

So why on a “Roaming Assist” thread am I talking about RF design? Well it’s simple; if there is not enough time for a device to roam to a neighbouring AP then the roam will fail (too little RF). If the RF power is too high the client will stick to the AP, even if the RF-Quality is poor. If you set static power and channels you can optimise the solution while you are completing the post installation survey. This is great when the environment does not change.

 

So let’s look at what we have been discussing - High Density Designs:

Interestingly most high-density designs only operate in a high-density mode for a relatively short period of time. People that are 90% water have an irritating tendency to absorbing some of the RF power! If the TX power is fixed then we can do nothing to counter this problem. Smart-RF will adapt, indeed if you look at the smart RF logs you can see this happening, as more people arrive TX power is slowly increased and as people leave the power is reduced.  

  

In addition to smart RF In WiNG we have an RFQ index, this varies from 0 (no information) to 5 which is Excellent.

Use the command:

show wireless client statistics rf on <rf-domain>

----------------------------------------------------------------------------------------------

  Retry AVG   : Average retransmissions per packet

  ERRORS      : Error Rate of rx errors and retries over good packet per second

  Q-INDEX     : RF Quality Index, higher value means better quality

(I)                  : RF matrix index where 0,1,2,3,4,5 maps to

(II)                  N/A, 1) Poor, 2) Fair, 3) Average, 4) Good, 5) Excellent

----------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------

MAC                  SIGNAL NOISE     SNR    TX-RATE    RX-RATE RETRY  ERRORS Q-INDEX    RETRY

                   (dbm)(I) (dbm)   db(I)  (Mbps)(I)  (Mbps)(I)   AVG   (pps)     (I)   (%)(I)

----------------------------------------------------------------------------------------------

50-DC-E7-88-33-B7    -60(4)   -96   36(5)      72(5)      65(5)  0.00       0       4 60.34(1)

D8-31-34-0B-04-9A    -73(3)   -99   26(4)      96(4)      81(4)  0.75       0       3 40.12(1)

----------------------------------------------------------------------------------------------

Total number of wireless clients displayed: 2

This is great to see how the client is performing on your network

 

Below is a smart RF-policy for US using only Non-DFS channels, note the US region has additional Non-DFS channels in unii band 3 

smart-rf-policy STORES

sensitivity custom

assignable-power 5GHz min 14

assignable-power 2.4GHz min 8

channel-list 5GHz 36,40,44,48,149,153,157,161,165

channel-width 5GHz 20MHz

smart-ocs-monitoring sample-count 5GHz 10

smart-ocs-monitoring sample-count 2.4GHz 15

smart-ocs-monitoring extended-scan-frequency 2.4GHz 0

coverage-hole-recovery snr-threshold 5GHz 10

coverage-hole-recovery snr-threshold 2.4GHz 10

neighbor-recovery dynamic-sampling     

 

This is the Channel list we normally use for Stores amended for Etsi regions

channel-list 5GHz 36,40,44,48,52,56,60,64.

If you are doing high density solution you could look at using all the channels

channel-list 5GHz 36,40,44,48,52,56,60,64,100,104,108,112,116,120,124,128,132,136,140,149,

 

Please minimise the number of SSID’s, only use 20Mhz Channels and remove the lower data rates.