Roaming between multiple APs

Hi,

I've read the thread on setting up two wireless routers in the howto forum, but it doesn't answer my question.

I have a DLink DWL-2100AP and another (it could be a DWL-2000AP) on the way. I want to enable roaming, so that a device will connect to whichever access point is the strongest, and change to the other one as necessary. I can't find anything in the admin website of the current AP to enable this, but I found an article on the web that suggests the roaming happens automatically.

From what I gather I set the SSID of the APs the same, but use different channels so the frequencies don't interfere.

Can someone clarify how the roaming part is setup please?

The wireless network is to be open, with no encryption/authentication, or routing/nating, there is just a server with a DHCP and an OpenVPN server. The encryption and authentication is handled by OpenVPN

Using Win XP the wireless client procedure is as follows( from http://download.microsoft.com/downlo...OHO_Tshoot.doc)

Scan for Wireless APs
Every 60 seconds, a Windows XP-based wireless client computer with a wireless network adapter that supports Wireless Auto Configuration performs a scan for the available wireless networks within range. When scanning, the wireless network adapter sends a series of Probe Request frames. Wireless APs within range of the scanning wireless client computer send a Probe Response frame that contain the capabilities of the wireless AP, such as supported speeds and security options.
Choose a Wireless AP
From the received Probe Response frames, the wireless client chooses a wireless AP with which it will attempt to authenticate and associate. The wireless client uses the following factors when determining which wireless AP to choose:
Wireless AP capabilities
The wireless AP advertises its capabilities in the Probe Response frame. If the wireless network adapter does not support the capabilities of the wireless AP as advertised in the Probe Response frame, the wireless client cannot choose the wireless AP. For example, if the wireless AP only supports WPA security options and the wireless network adapter does not support WPA, the wireless client cannot choose the wireless AP. Another example is when the wireless AP only supports 802.11g and the wireless adapter only supports 802.11a.
Wireless network name matches a preferred network
Windows XP Wireless Auto Configuration maintains a list of preferred wireless networks corresponding to the wireless networks that a user of the computer has chosen to connect to. If the wireless network name, also known as the SSID, does not match the name of a wireless network in the preferred list, then by default Windows XP cannot connect to the wireless AP. If there are Probe Response frames from multiple wireless networks that are in the preferred list, then Wireless Auto Configuration chooses the most preferred wireless network (the highest one in the list).
If the wireless network names of the received Probe Response frames do not match a preferred network, Windows XP prompts the user with a "One or more wireless networks are available" or "Connect to a wireless network" message in the notification area of the Windows XP desktop. When the user clicks this message, they can then choose to connect to a new wireless network.
Signal strength
The wireless network adapter of the wireless client chooses the wireless AP with the highest signal strength for the wireless network name that is highest
in the preferred list.


The client chooses which AP it considers to have the greatest signal strength.


802.11r , IEEE 802.11r - Wikipedia, the free encyclopedia , has not been ratified yet so it is unlikely you will find any set up in SOHO routers and AP's to implement roaming. Any roaming that takes place at the moment will be dependent on the signal strength seen by the client device.

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I'm actually using 802.11g.

OK, so the roaming mode is done on the client. So, there is nothing specific to be done with the AP, that explains why I'm struggling to find info on the subject. I think it'll be a case of waiting for this other AP and to have a play.

When I take my machine to uni it'll do automatic roaming, moving from one wireless access point to the other, but it isn't seemless. TCP connections initiated when associated with one AP break when I move to another AP, so this sounds like the client is doing the roaming here and this is the connectivity I can expect from my two APs?

Thanks for the in-depth info.