Active Roaming

Brent Simpson

Can anyone point me towards any documentation on what active roaming is and how it works? Have a site with 4 access points and MVP-5200i doesn't seem to want to connect to each AP as I'm walking around? Active Roaming is enabled / lastest firmware installed. Maybe it's just me?

vining

You have to have your APs of channels 1,6 & 11 so with your 4 AP set up one channel wil need to be duplicated and they should be the furthest apart or at least far apart with the most solid structure between them. I still think they're a little stubborn and don't disconnect re-connect as quickly as you might think they should but that's dependant on the threshold levels that warrant a disconnect when a stronger AP is present. It may be you have to lose the connection completely before it will grab the hottest channel. Obviously you don't want to drop a connection while data is flowing with out just cause and the mere fact that a stronger AP is present now isn't really just cause if the one connected is still strong enough to maintain the data flow.

I've yet to play with my managed wireless network (Cisco APs w/ wireless controller still in boxes) that actually managed the handoffs which is vital for wireless VOIP telephone systems. I'd like to see what differences if any it will make on the MVP reliability.

Brent Simpson

Channels

AP channels are distributed 11, 6, 1, 11 across the building so both Ch 11's are furtherest apart - 40 mtrs including 7 concrete block walls plus or minus a ton of reinforcing!

The SSID's are different so I can tell which AP the TS was connected to - should they be the same or different?

Thnx
Simmo

vining

Same SSID's in all 4.

Brent Simpson

SSID's

Thanks! That may explain why the TS is not roaming properly!

Simmo

[Deleted User]

Some Roaming Algorithm specifics

FYI, The roaming function in the WLAN driver is enabled when the signal level (to the currently connected AP) drops below -65dBm. At that point the panel will begin "active probing" for APs with the SSID that has been originally configured in the panel. But it will only switch to another AP if the signal strength of the new AP is 10dB or better than the current AP.
In the case where the signal is completely lost and a disconnect occurs, roaming is essentially discontinued. At this point the panel will actively probe for the configured SSID and the first AP that responds (may or may not be the closest or the strongest signal) will get connected. Then the roaming algorithm will again start monitoring the signal strength.
You can see the signal level in "Wireless Statistics" under Protected Setup:Tools:Panel Statistics menu.

Brent Simpson

I can see more bettera now!

Thanks Guy's, it helps to know these things. A little bit of understanding goes along way in diagnosing the problems out in the field more easily.

And it's great to see AMX engineering guy's getting involved with these discussions - 10 points to AMX!

Brent Simpson

Thanks guy's, I've changed the SSID to all same and roaming works well. Incidentially, his iPhone also vnc's into the 5200i beautifully. Client is very impressed! Just got to get the IP camera's onto 5200i with PTZ control...